Answer:
(a) P(E∪F)= 0.8
(b) P(Ec)= 0.4
(c) P(Fc)= 0.7
(d) P(Ec∩F)= 0.8
Step-by-step explanation:
(a) It is called a union of two events A and B, and A ∪ B (read as "A union B") is designated to the event formed by all the elements of A and all of B. The event A∪B occurs when they do A or B or both.
If the events are not mutually exclusive, the union of A and B is the sum of the probabilities of the events together, from which the probability of the intersection of the events will be subtracted:
P(A∪B) = P(A) + P(B) - P(A∩B)
In this case:
P(E∪F)= P(E) + P(F) - P(E∩F)
Being P(E) = 0.6, P(F) = 0.3 and P(E ∩ F) = 0.1
P(E∪F)= 0.6 + 0.3 - 0.1
P(E∪F)= 0.8
(b) The complement of an event A is defined as the set that contains all the elements of the sample space that do not belong to A. The Complementary Rule establishes that the sum of the probabilities of an event and its complement must be equal to 1. So, if P (A) is the probability that an event A occurs, then the probability that A does NOT occur is P (Ac) = 1- P (A)
In this case: P(Ec)= 1 - P(E)
Then: P(Ec)= 1 - 0.6
P(Ec)= 0.4
(c) In this case: P(Fc)= 1 - P(F)
Then: P(Fc)= 1 - 0.3
P(Fc)= 0.7
(d) The intersection of two events A and B, designated as A ∩ B (read as "A intersection B") is the event formed by the elements that belong simultaneously to A and B. The event A ∩ B occurs when A and B do at once.
As mentioned, the complementary rule states that the sum of the probabilities of an event and its complement must equal 1. Then:
P(Ec intersection F) + P(E intersection F) = P(F)
P(Ec intersection F) + 0.1 = 0.3
P(Ec intersection F)= 0.2
Being:
P(Ec∪F)= P(Ec) + P(F) - P(Ec∩F)
you get:
P(Ec∩F)= P(Ec) + P(F) - P(Ec∪F)
So:
P(Ec∩F)= 0.4 + 0.3 - 0.2
P(Ec∩F)= 0.8
3. A jogger runs 4 miles on Monday, 5 miles on
Tuesday, 3 miles on Wednesday, and 5 miles on
Thursday. He doesn't run on Friday. How many
miles did he run in all?
Answer:
17 miles
Step-by-step explanation:
4+5+5+3=17
Dada la recta L: 3x - 2y + 1 = 0, ¿cual es la pendiente de la recta L1?
Answer:
La pendiente de la recta L es [tex]\frac{3}{2}[/tex].
Step-by-step explanation:
La recta está presentada en su forma implícita, es decir, que está bajo la forma:
[tex]f(x,y) = 0[/tex]
Para determinar la pendiente de la recta, se debe transformarla a su forma explícita, cuya fórmula es:
[tex]y = m \cdot x + b[/tex]
Donde:
[tex]x[/tex] - Variable independiente, adimensional.
[tex]y[/tex] - Variable dependiente, adimensional.
[tex]m[/tex] - Pendiente, adimensional.
[tex]b[/tex] - Intercepto, adimensional.
Entonces:
[tex]3\cdot x - 2\cdot y + 1 = 0[/tex]
[tex]2\cdot y = 3\cdot x +1[/tex]
[tex]y = \frac{3}{2}\cdot x + \frac{1}{2}[/tex]
Por simple inspección, se determina que la pendiente de la recta L es [tex]\frac{3}{2}[/tex].
A study was conducted to assess the effects that occur when children are exposed to cocaine before birth. Children were tested at age 4 for object assembly skill, which was described as a task requiring visual spatial skills related to mathematical competence. The 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0 Use a 0.05 significance level to test the claim that prenatal cocaine exposure is associated with lower scores of four year old children on the test of object assembly.
What are null and alternative hypothesis? What is test statistics?
Answer:
We conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
Step-by-step explanation:
We are given that the 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0.
Let [tex]\mu_1[/tex] = population mean score for children born to cocaine users.
[tex]\mu_2[/tex] = population mean score for children not exposed to cocaine.
So, Null Hypothesis, : = 490 {means that the prenatal cocaine exposure is not associated with lower scores of four-year-old children on the test of object assembly}
Alternate Hypothesis, : 490 {means that the prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly}
The test statistics that will be used here is Two-sample t-test statistics because we don't know about population standard deviations;
T.S. = [tex]\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }[/tex] ~ [tex]t__n_1_+_n_2_-_2[/tex]
where, [tex]\bar X_1[/tex] = sample mean score of children born to cocaine users = 7.3
[tex]\bar X_2[/tex] = sample mean score of children not exposed to cocaine = 8.2
[tex]s_1[/tex] = sample standard deviation for children born to cocaine users = 3
[tex]s_2[/tex] = sample standard deviation for children not exposed to cocaine = 3
[tex]n_1[/tex] = sample of children born to cocaine users = 190
[tex]n_2[/tex] = sample of children not exposed to cocaine = 186
Also, [tex]s_p=\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }[/tex] = [tex]\sqrt{\frac{(190-1)\times 3^{2}+(186-1)\times 3^{2} }{190+186-2} }[/tex] = 3
So, the test statistics = ~
= -2.908
The value of t-test statistics is -2.908.
Now, at a 0.05 level of significance, the t table gives a critical value of -1.645 at 374 degrees of freedom for the left-tailed test.
Since the value of our test statistics is less than the critical value of t as -2.908 < -1.645, so we have sufficient evidence to reject our null hypothesis as the test statistics will fall in the rejection region.
Therefore, we conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
In the null hypothesis, a test always forecasts no effect, while the alternate theory states the research expectation impact, and calculation as follows:
Null and alternative hypothesis:Calculating the pooled estimator of [tex]\sigma^2[/tex], denoted by [tex]S^2_p[/tex], is defined by
[tex]\to \bold{S^2_p= \frac{(n_1 - 1) S^2_1+ (n_2 - 1)S^2_2}{n_1 + n_2 - 2}}[/tex]
Null hypothesis:
[tex]\to H_0 : \mu_1 - \mu_2 = \Delta_0\\[/tex]
Test statistic:
[tex]\to T_0=\frac{\bar{X_1}- \bar{X_2} -\Delta_0}{S_p \sqrt{\frac{1}{n_1}+\frac{1}{n_2}}} \\\\[/tex]
Alternative Hypothesis:
[tex]H_1 : \mu_1 -\mu_2 \neq \Delta_0\\\\ H_1 : \mu_1 -\mu_2 > \Delta_0\\\\H_1 : \mu_1 -\mu_2 < \Delta_0\\\\[/tex]
Rejection Criterion
[tex]t_0 > t_{\frac{\alpha}{2} , n_1+n_2 -2}\ \ \ or\ \ \ t_0 < - t_{\frac{\alpha}{2} , n_1+n_2 -2} \\\\t_o > t_{\alpha , n_1+n_2 -2} \\\\t_o > -t_{\alpha , n_1+n_2 -2}[/tex]
Given value:
[tex]\to S_p=9\\\\\to \Delta_0=0\\\\\to t_0=-\frac{0.9}{3(\sqrt{(\frac{1}{190}+\frac{1}{186})})}=-2.9\\\\\to t_{0.05,374}=1.645\\\\[/tex]
here
[tex]\to t_0 < -t_{0.05,374}[/tex]
hence rejecting the [tex]H_0[/tex]
Since there should be enough evidence that prenatal cocaine exposure is linked to inferior item assembly scores in 4-year-olds.
Find out more about the alternative hypothesis here:
brainly.com/question/18831983
Choose the inequality that represents the following graph.
Answer:
option a
Step-by-step explanation:
give person above brainliest :)
Stephanie is twice as old as her sister Rosa. If Stephanie is 18 years old, how old is Rosa?
Answer:
rose. is. 18/2=9 years old
Answer:
Stephanie is 18years old and she is twice older than her sister
so rosa is 18÷2(since stephanie is twice older than rosa
so rosa is 9 years old
A study was conducted by a research center. It reported that most shoppers have a specific spending limit in place while shopping online. The reports indicate that men spend an average of $240 online before they decide to visit a store. If the spending limit is normally distributed and the standard deviation is $20.
A. Find the probability that a male spent less than $210 online before deciding to visit a store.
B. Find the probability that a male spent between $270 and $300 online before deciding to visit a store.
C. Ninety percent of the amounts spent online by a male before deciding to visit a store are less than what value?
Answer:
(A) The probability that a male spent less than $210 online before deciding to visit a store is 0.0668.
(B) The probability that a male spent between $270 and $300 online before deciding to visit a store is 0.0655.
(C) Ninety percent of the amounts spent online by a male before deciding to visit a store is less than $265.632.
Step-by-step explanation:
We are given that the reports indicate that men spend an average of $240 online before they decide to visit a store. If the spending limit is normally distributed and the standard deviation is $20.
Let X = the spending limit
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = mean spending limit = $240
[tex]\sigma[/tex] = standard deviation = $20
So, X ~ Normal([tex]\mu=\$240,\sigma^{2} =\$20^{2}[/tex])
(A) The probability that a male spent less than $210 online before deciding to visit a store is given by = P(X < $210)
P(X < $210) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{\$210-\$240}{\$20}[/tex] ) = P(Z < -1.50) = 1 - P(Z [tex]\leq[/tex] 1.50)
= 1 - 0.9332 = 0.0668
The above probability is calculated by looking at the value of x = 1.50 in the z table which has an area of 0.9332.
(B) The probability that a male spent between $270 and $300 online before deciding to visit a store is given by = P($270 < X < $300)
P($270 < X < $300) = P(X < $300) - P(X [tex]\leq[/tex] $270)
P(X < $300) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{\$300-\$240}{\$20}[/tex] ) = P(Z < 3) = 0.9987
P(X [tex]\leq[/tex] $270) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{\$270-\$240}{\$20}[/tex] ) = P(Z [tex]\leq[/tex] 1.50) = 0.9332
The above probability is calculated by looking at the value of x = 3 and x = 1.50 in the z table which has an area of 0.9987 and 0.9332 respectively.
Therefore, P($270 < X < $300) = 0.9987 - 0.9332 = 0.0655.
(C) Now, we have to find ninety percent of the amounts spent online by a male before deciding to visit a store is less than what value, that is;
P(X < x) = 0.90 {where x is the required value}
P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{x-\$240}{\$20}[/tex] ) = 0.90
P(Z < [tex]\frac{x-\$240}{\$20}[/tex] ) = 0.90
In the z table, the critical value of z that represents the bottom 90% of the area is given as 1.2816, i.e;
[tex]\frac{x-\$240}{\$20}=1.2816[/tex]
[tex]x-240=1.2816\times 20[/tex]
[tex]x=240 + 25.632[/tex]
x = 265.632
Hence, Ninety percent of the amounts spent online by a male before deciding to visit a store is less than $265.632.
Mathematical induction is:
Answer:
The third option.
Step-by-step explanation:
Mathematical induction is a 2 step mathematical technique which is used to prove a statement, a formula or a theorem is true for every natural number.
Step 1 (Base step) - It proves that a statement is true for the initial value.
Step 2 (Inductive step) - It proves that if the statement is true for the nth iteration (or number n), then it is also true for (n + 1)th iteration (or number n + 1)
Hope this helps.
Please mark Brainliest.
Answer:
A method of improving statments
Step-by-step explanation:
"Mathematical Induction is a mathematical technique which is used to prove a statement, a formula or a theorem is true for every natural number."
Can someone help? This hard
Answer:
The expression = [tex] \frac{40}{y - 16} [/tex]
Value of the expression = 4 (when y is 20)
Step-by-step explanation:
Quotient simply means the result you get when you divide two numbers. Thus, dividend (the numerator) ÷ divisor (the denominator) = quotient.
From the information given to us here,
the dividend = 40
the divisor = y - 16
The quotient = [tex] \frac{40}{y - 16} [/tex]
There, the expression would be [tex] \frac{40}{y - 16} [/tex]
Find the value of the expression when y = 20.
Plug in 20 for y in the expression and evaluate.
[tex] \frac{40}{y - 16} [/tex]
[tex] = \frac{40}{20 - 16} [/tex]
[tex] = \frac{40}{4} = 10 [/tex]
The value of the expression, when y is 20, is 4.
Evaluate 26 + a if a = 8
Answer:
34
Step-by-step explanation:
= 26 + 8
= 34
A certain dataset of systolic blood pressure measurements has a mean of 80 and a standard deviation of 3. Assuming the distribution is bell-shaped and we randomly select a measurement:
a) What percentage of measurements are between 71 and 89?
b) What is the probability a person's blood systolic pressure measures more than 89?
c) What is the probability a person's blood systolic pressure being at most 75?
d) We should expect 15% of patients have a blood pressure below what measurement?
e) Would it be unusual for 3 patients to have a mean blood pressure measurement of more than 84? Explain.
Answer:
Explained below.
Step-by-step explanation:
Let X = systolic blood pressure measurements.
It is provided that, [tex]X\sim N(\mu=80,\sigma^{2}=3^{2})[/tex].
(a)
Compute the percentage of measurements that are between 71 and 89 as follows:
[tex]P(71<X<89)=P(\frac{71-80}{3}<\frac{X-\mu}{\sigma}<\frac{89-80}{3})[/tex]
[tex]=P(-3<Z<3)\\=P(Z<3)-P(Z<-3)\\=0.99865-0.00135\\=0.9973[/tex]
The percentage is, 0.9973 × 100 = 99.73%.
Thus, the percentage of measurements that are between 71 and 89 is 99.73%.
(b)
Compute the probability that a person's blood systolic pressure measures more than 89 as follows:
[tex]P(X>89)=P(\frac{X-\mu}{\sigma}>\frac{89-80}{3})[/tex]
[tex]=P(Z>3)\\=1-P(Z<3)\\=1-0.99865\\=0.00135\\\approx 0.0014[/tex]
Thus, the probability that a person's blood systolic pressure measures more than 89 is 0.0014.
(c)
Compute the probability that a person's blood systolic pressure being at most 75 as follows:
Apply continuity correction:
[tex]P(X\leq 75)=P(X<75-0.5)[/tex]
[tex]=P(X<74.5)\\\\=P(\frac{X-\mu}{\sigma}<\frac{74.5-80}{3})\\\\=P(Z<-1.83)\\\\=0.03362\\\\\approx 0.034[/tex]
Thus, the probability that a person's blood systolic pressure being at most 75 is 0.034.
(d)
Let x be the blood pressure required.
Then,
P (X < x) = 0.15
⇒ P (Z < z) = 0.15
⇒ z = -1.04
Compute the value of x as follows:
[tex]z=\frac{x-\mu}{\sigma}\\\\-1.04=\frac{x-80}{3}\\\\x=80-(1.04\times3)\\\\x=76.88\\\\x\approx 76.9[/tex]
Thus, the 15% of patients are expected to have a blood pressure below 76.9.
(e)
A z-score more than 2 or less than -2 are considered as unusual.
Compute the z score for [tex]\bar x[/tex] as follows:
[tex]z=\frac{\bar x-\mu}{\sigma/\sqrt{n}}[/tex]
[tex]=\frac{84-80}{3/\sqrt{3}}\\\\=2.31[/tex]
The z-score for the mean blood pressure measurement of 3 patients is more than 2.
Thus, it would be unusual.
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Answer:
32.8 miles
Step-by-step explanation:
Amy is driving to Seattle. Suppose that the remaining distance to drive (in miles) is a linear function of her driving time (in minutes). When graphed, the function gives a line with a slope of -0.95. See the figure below. Amy has 48 miles remaining after 31 minutes of driving. How many miles will be remaining after 47 minutes of driving?
Answer: The general equation of a line is given as y = mx + c, where m is the slope of the line and c is the intercept on the y axis. Given that the slope is -0.95, substituting in the general equation :
y = -0.95x + c
Amy has 48 miles remaining after 31 minutes of driving, to find c, we substitute y = 48 and x = 31. Therefore:
48 = -0.95(31) + c
c = 48 + 0.95(31)
c = 48 + 29.45
c = 77.45
The equation of the line is
y = -0.95x + 77.45
After 47 minutes of driving, the miles remaining can be gotten by substituting x = 47 and finding y.
y = -0.95(47) + 77.45
y = -44.65 + 77.45
y = 32.8 miles
What is x? Round to the nearest tenth
Answer:
x = 38.7
Step-by-step explanation:
Since this is a right triangle, we can use trig functions
tan theta = opp / adj
tan x = 8/10
taking the inverse tan of each side
x = tan ^-1 (8/10)
x=38.65980825
To the nearest tenth
x = 38.7
first second and last term of Ap are a,b,2a respectively, find its sum
Answer:
(3ab)/(2(b-a))
Step-by-step explanation:
The n-th term of an arithmetic progression is ...
an = a1 +d(n -1)
Then the value of n is ...
n = (an -a1)/d +1
The sum of an arithmetic progression is the product of the number of terms and the average of the first and last terms. In this sequence, the common difference d is ...
d = (b -a)
So, the sum is ...
Sn = (a +2a)/2·((2a -a)/(b -a) +1)
Sn = (3ab)/(2(b-a)) . . . . sum of the arithmetic progression
__
Example:
The sequence 1, 1.5, 2 has ...
a = 1, b = 1.5
Its sum is given by the above formula as ...
Sn = 3(1)(1.5)/(2(1.5 -1)) = 4.5/(2(.5)) = 4.5 = 1 + 1.5 + 2 . . . . yes
The Rogers family drove 220 miles in 5.5 hours. How many miles would they drive at this same rate in 4 hours? A. 88 mi B. 147 mi C. 160 mi D. 179 mi Please show ALL work! <3
Answer:
160 miles
Step-by-step explanation:
We can use a ratio to solve
220 miles x miles
--------------- = ----------------------
5.5 hours 4 hours
Using cross products
220 *4 = 5.5x
880 = 5.5x
Divide each side by 5.5
880/5.5 = x
160 miles
Answer:
[tex]\large \boxed{\mathrm{C. \ 160 \ miles}}[/tex]
Step-by-step explanation:
We can solve this problem by ratios.
Let x be the missing value.
[tex]\displaystyle \frac{220}{5.5} =\frac{x}{4}[/tex]
Cross multiply.
[tex]5.5 \times x = 220 \times 4[/tex]
[tex]5.5x=880[/tex]
Divide both sides by 5.5.
[tex]\displaystyle \frac{5.5x}{5.5} =\frac{880}{5.5}[/tex]
[tex]x=160[/tex]
What is the distance between y=2x+4 and y=2x-1?
Answer:
Y=2(1)+4
Y=2+4
Y=6
Step-by-step explanation:
Please follow me
The points (0,3) and (1,12) are solutions of an exponential function. What is the equation of the exponential function?
Answer:
[tex]f(x) =3\,*\,\,4^x[/tex]
Step-by-step explanation:
to find the equation of an exponential function, just points on the function's graph are needed.
Recall that the exponential function has a general expression given by:
[tex]f(x) = a \,e^{b\,x}[/tex]
so we impose the condition for the function going through the first point (0,3) as:
[tex]f(0) = a \,e^{b\,(0)}= 3\\a\,e^0=3\\a\,(1)=3\\a = 3[/tex]
Now,knowing the parameter a, we can find the parameter b using the other point:
[tex]f(1) = 3 \,e^{b\,x}= 12\\3\,e^{b\,(1)}=12\\e^b=12/3\\e^b=4\\b=ln(4)[/tex]
Therefore, the function can be written as:
[tex]f(x) = 3 \,e^{ln(4)\,x}=3\,\,\,4^x[/tex]
Answer:
C)
h(x) = 3(4)x
What is the slope of the line?
A. −9/5
B. 5/9
C. −5/9
D. 9/5
Answer: -9/5
Step-by-step explanation: To find the slope, we must understand that the slope of a line is defined as the ratio rise/run.
The rise is the vertical direction of the line and the
run is the horizontal direction of the line.
So to start, I am going to pick 2 points on this line.
You want to find points where the line crosses the four corners.
In the diagram, those would be the points (-4, 5) and (1, -4).
Now, we can use slope formula.
Slope = y₂ - y₁ / x₂ - x₁
So we have -4 - 5/1 - -4 which simplifies to -9/5.
So the slope is -9/5.
Answer:
the answer is -9/5 100%
Step-by-step explanation:
1/3 is part of which set of numbers?
Answer:
[tex] \frac{1}{3} [/tex]Rational number as denominator is not equal to zero and numerator is a integer.
Rational numbers. denoted by [tex] \mathbb Q[/tex]
1/3 is clearly not a natural number or integer.
it is a fraction, =0.333 , it fits the definition of rational number ([tex] \frac pq [/tex]).
(1-Cota)^2
+(tana-1)^2=4cosec2a(cosec2a-1)
Answer:
Step-by-step explanation:
(1-CotA)² + (tanA-1)² = 4csc2A(csc2A-1)
To prove this equation we will take the expression given in left hand side and will convert it into the expression given in right hand side of the equation.
L.H.S. = (1-CotA)² + (tanA-1)²
= 1 + Cot²A - 2CotA + 1 + tan²A - 2tanA
= cosec²A - 2CotA + Sec²A - 2tanA
[Since, (1 + Cot²A = cosec²A) and (1 + tan²A = Sec²A)]
= (cosec²A + Sec²A) - 2(CotA + tanA)
= [tex](\frac{1}{\text{SinA}})^{2}+(\frac{1}{CosA} )^{2}-2\text{(tanA}+\frac{1}{\text{tanA}})}[/tex]
= [tex]\frac{1}{(\text{SinA.CosA})^2}-2(\frac{tan^2A+1}{tanA} )[/tex]
= [tex]\frac{4}{\text{(Sin2A})^{2}}-4(\frac{1}{\text{Sin2A}} )[/tex]
[Since 2SinA.CosA = Sin2A and [tex]\frac{2(\text{tanA})}{1+\text{tan}^{2}A}=\text{Sin2A}[/tex]]
= 4Cosec²2A - 4Cosec2A
= 4Cosec2A(Cosec2A - 1)
= R.H.S. (Right hand side)
Hence the equation is proved.
What is the solution to the following system of equations? 3x-2y=12 6x - 4y = 24
Answer:
D question,somewhat confusing, itsit's like simultaneous equation,but values are different
Answer:
x = 4 + 2y/3
Step-by-step explanation:
An Internet service provider is implementing a new program based on the number of connected devices in each household currently,customers are charged a flat rate of $175 per month.the new plan would charge a flat rate of $94 plus an additional $4.50 per device connected to the network.find the number of devices,x,for which the cost of the new plan is less than the cost of the current plan.
Answer:
(x=6) is less than 18 which would give you the cost of the current plan
Step-by-step explanation:
If you take six, first you must multiply 4.50 by 6, ($27) then add it, to $94, giving you $121. Now we have to find which phone will give us the same cost, for this I choose 18. if you do 18 x 4.50, you get $81, and if you add this to 94, it gives you 175.
Nisha is looking out the window of her apartment building at a sculpture in a park across the street. The top of Nisha's window is 80 feet from the ground. The angle of depression from the top of Nisha's window to the bottom of the sculpture is 20°. How far away from the building is the sculpture? Round your answer to the nearest hundredth.
Answer:
219.80 feet
Step-by-step explanation:
Tan 20= 80/b
Tan 20= 0.363970234266
(0.363970234266)b=80
b= 219.80 feet
The distance between the sculpture and the bottom of the building is required.
The distance between the building and sculpture is 219.80 feet.
Trigonometry[tex]\theta[/tex] = Angle of depression = Angle of elevation = [tex]20^{\circ}[/tex]
p = Height of building = 80 feet
b = Required length
From the trigonometric ratios we have
[tex]\tan\theta=\dfrac{p}{b}\\\Rightarrow b=\dfrac{p}{\tan\theta}\\\Rightarrow b=\dfrac{80}{\tan 20}\\\Rightarrow b=219.80\ \text{feet}[/tex]
Learn more about trigonometry:
https://brainly.com/question/23899312
quanto e 45x12 (500-450-550)
Answer:
see below
Step-by-step explanation:
the simple answer is -270000
A boutique wants to make at least $127 profit from purses this week. The boutique earns $7 profit from each purse. How many purses must be sold?
Answer:
19 purses
Step-by-step explanation:
Set up an inequality where x represents the number of purses:
127 [tex]\geq[/tex] 7x
Solve for x by dividing each side by 7:
18.14 [tex]\geq[/tex] x
Round up to 19 because purses have to be whole
So, 19 purses have to be sold.
Reducing scrap of 4-foot planks of hardwood is an important factor in reducing cost at a wood-floor manufacturing company. Accordingly, engineers at Lumberworks are investigating a potential new cutting method involving lateral sawing that may reduce the scrap rate. To examine its viability, two independent, random, representative samples of planks were examined. One sample contained 200 planks which were sawed using the old method. The other sample contained 400 planks which were sawed using the new method. Sixty-two of the 200 planks were scrapped under the old method of sawing, whereas 36 of the 400 planks were scrapped under the new method.
Required:
a. Construct the 90% confidence interval for the difference between the population scrap rates between the old and new methods, respectively.
b. Write the null and alternative hypotheses to test for differences in the population scrap rates between the old and new cutting methods, respectively.
c. Using the part a results, can we conclude at the 10% significance level that the scrap rate of the new method is different than the old method?
Answer:
The critical value for two tailed test at alpha=0.1 is ± 1.645
The calculated z= 9.406
Step-by-step explanation:
Formulate the hypotheses as
H0: p1= p2 there is no difference between the population scrap rates between the old and new cutting methods
Ha : p1≠ p2
Choose the significance level ∝= 0.1
The critical value for two tailed test at alpha=0.1 is ± 1.645
The test statistic is
Z = [tex]\frac{p_1- p_2}\sqrt pq(\frac{1}{n_1} + \frac{1}{n_2})[/tex]
p1= scrap rate of old method = 62/200=0.31
p2= scrap rate of new method = 36/400= 0.09
p = an estimate of the common scrap rate on the assumption that the two rates are same.
p = n1p1+ n2p2/ n1 + n2
p =200 (0.31) + 400 (0.09) / 600
p= 62+ 36/600= 98/600 =0.1633
now q = 1-p= 1- 0.1633= 0.8367
Thus
z= 0.31- 0.09/ √0.1633*0.8367( 1/200 + 1/400)
z= 0.301/√ 0.13663( 3/400)
z= 0.301/0.0320
z= 9.406
The calculated value of z falls in the critical region therefore we reject the null hypothesis and conclude that the 10% significance level that the scrap rate of the new method is different from the old method.
Customers arrive at a rate of 24 people per hour to a bank. Assume that the number of customers arriving can be described using the Poisson distribution. What is the probability that at most 30 customers arrive in the next hour
Answer:
0.90415
Step-by-step explanation:
Given the following :
Arrival rate = mean(μ) = 24
Probability that at most 30 customers arrive in the next hour:
The poisson distribution formula :
P(x, μ) = [(e^-μ) * (μ^x)] / x!
Where :
e = euler's constant
P(x ⩽ 30) = p(0) + p(1) + p(2) +.... + p(30)
Using the online poisson probability distribution calculator :
P(x ⩽ 30, 24) = 0.90415
Therefore there is about 90.4% probability that at most 30 customers will arrive in the next hour.
Cases Prudence has a special (cubic) die. The values on its face are the integers from 1 to 6, but they are not arranged ae in a normal die. When Prudence first tosses the die, the sum of the values on the four side faces is 15. In her second toss, the sum of these values is 12. Find what value appears in the face opposite 6 on Prudence’s special die. (Hint: what are possible values for the top and bottom face when the sum of the side faces is 12).
Answer: 3
Step-by-step explanation:
first, we know that:
1 + 2 + 3 + 4 +5 +6 = 21
Now, which two numbers we should take out in order to have 15?
we can remove the 2 and the 4, or the 1 and the 5.
so here we have two possibilities, 2 and 4 are opposite, or 1 and 5 are opposite (they are located in opposite faces of the die)
in the other arrange, we have that removing two numbers we should get 12.
in order to reach 12, we should remove two numbers that add 9 together.
those can be 4 and 5, or 6 and 3.
Now, notice that in the first restriction we have that:
Or 2 and 4 are opposite,
or 1 and 5 are opposite.
So 4 and 5 can never be opposite, so we should have that 6 and 3 are opposite.
Then we can affirm that the value that appears in the face opposite to the 6, is the 3.
Smoking by Race for Males Aged 18-24
Smoker Nonsmoker Row Total
(S) (N)
White(W) 290 560 850
Black(B) 30 120 150
Column Total 320 680 1,000
Calculate the probabilities given below (Round your answers to 4 decimal places.):
i. P(S) 0.3200
ii. P(W) 0.8500
iii. P(S | W) 0.2720
iv. P(S | B) 0.0300
v. P(S and W) 0.9062
vi. P(N and B) 0.1765
Answer:
(i) 0.32 (ii) 0.85
(iii) 0.3412 (iv) 0.20
(v) 0.29 (vi) 0.12
Step-by-step explanation:
The data provided is as follows:
Race Smoker (S) Nonsmoker (N) Row Total
White(W) 290 560 850
Black(B) 30 120 150
Column Total 320 680 1,000
(i)
Compute the value of P (S) as follows:
[tex]P(S)=\frac{n(S)}{N}=\frac{320}{1000}=0.32[/tex]
P (S) = 0.32.
(ii)
Compute the value of P (W) as follows:
[tex]P(W)=\frac{n(W)}{T}=\frac{850}{1000}=0.85[/tex]
P (W) = 0.85.
(iii)
Compute the value of P (S|W) as follows:
[tex]P(S|W)=\frac{n(S\cap W)}{n(W)}=\frac{290}{850}=0.3412[/tex]
P (S|W) = 0.3412.
(iv)
Compute the value of P (S|B) as follows:
[tex]P(S|B)=\frac{n(S\cap B)}{n(B)}=\frac{30}{150}=0.20[/tex]
P (S|W) = 0.20.
(v)
Compute the value of P (S∩W) as follows:
[tex]P(S\cap W)=\frac{n(S\cap W)}{T}=\frac{290}{1000}=0.29[/tex]
P (S∩W) = 0.29.
(vi)
Compute the value of P (N∩B) as follows:
[tex]P(N\cap B)=\frac{n(N\cap B)}{T}=\frac{120}{1000}=0.12[/tex]
P (S∩W) = 0.12.
A random variable is not normally distributed, but it is mound shaped. It has a mean of 14 and a standard deviation of 3. If you take a sample of size 10, can you say what the shape of the sampling distribution for the sample mean is
Answer:
Step-by-step explanation:
from the question,
the mean 14
the standard deviation is 3
and sample size is 10.
since the n which is the sample size is 10, then the distribution is mound shaped.
why?
this is due to the fact that the random variable from which we took the sample is mound shaped.
The sampling distribution of the mean is normally distributed although the question says the random variable is not normally distributed. so the shape is bell shaped and normally distributed.
the standard deviation of the mean is
3/√10
= 0.948
I need help please help me
Answer: 72576m7
Step-by-step explanation:
2m x 8m x 6m x 9m x 7m x 6m x 2m
All together equals my answer 72576m7
Hope this helps!
