Answer:
The question is not complete, below is the complete question:
What is meant by the term 90% confident? when constructing a confidence interval for a mean?
a. If we took repeated samples, approximately 90% of the samples would produce the same confidence interval.
b. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the sample mean.
c. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean.
d. If we took repeated samples, the sample mean would equal the population mean in approximately 90% of the samples.
Answer:
The correct answer is:
If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean. (c)
Step-by-step explanation:
a 90% confidence level means that if repeated samples were taken, 9 out of 10 times, the confidence intervals of the sample chosen will be close to the mean (true value), which is a true representation of the population parameter. when using confidence intervals, there are always margins of allowable accuracy, and this is suggested by using standard diviations snd variances.
I attached a simple document to this answer that will give you more insight into confidence intervals used in statistics.
Please help. I’ll mark you as brainliest if correct
Answer:
bonds: $65,000
cd's: $30,000
stocks: $20,000
Step-by-step explanation:
b + c + s = 115000
0.045b + 0.0325c + 0.082s = 5540
b = c + 35000
b = 65,000
c = 30,000
s = 20,000
A passenger train traveled 180 miles in the same amount of time it took a freight train to travel 120 miles. The rate of the freight train was 15 miles per hour slower than the rate of the passenger train. Find the rate of the passenger train.
Answer:
The passenger train is moving at 45 miles per hour
Step-by-step explanation:
Let the amount of time it took the two trains to travel the distance = t.
Since the two trains traveled the distance at the same time,
Rate of the passenger train =[tex]\frac{180}{t}[/tex]
Rate of the freight train = [tex]\frac{120}{t}[/tex]
Where t is in hours.
From the problem, we can see that the rate of the freight train was 15 miles per hour slower than the rate of the passenger train. Mathematically, we can represent this as
[tex]\frac{120}{t}= \frac{180}{t}-15[/tex]
from the above equation, we can now get our value for t as
[tex]\frac{120-180}{t}=-15\\\frac{-60}{t}=-15\\t=4 hours[/tex]
We have our time of travel for the two trains as 4 hours.
The rate of the passenger train can now be calculated by 180/4 = 45 miles per hour
Among a simple random sample of 331 American adults who do not have a four-year college degree and are not currently enrolled in school, 48% said they decided not to go to college because they could not afford school.
Part II: Exercise 6.16 presents the results of a poll where 48% of 331 Americans who decide to not go to college do so because they cannot afford it.
#1: Calculate a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it, and interpret the interval in context.
(a) lower bound: ______ (please round to four decimal places)
(b) upper bound: _____ (please round to four decimal places)
#2: Interpret the confidence interval in context:
(A) We can be 90% confident that our confidence interval contains the sample proportion of Americans who choose not to go to college because they cannot afford it
(B) 90% of Americans choose not to go to college because they cannot afford it
(C) We can be 90% confident that the proportion of Americans who choose not to go to college because they cannot afford it is contained within our confidence interval
#3: Suppose we wanted the margin of error for the 90% confidence level to be about 1.5%. How large of a survey would you recommend?
(a) A survey should include at least ________ people.
Answer:
(1) Therefore, a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it is [0.4348, 0.5252].
(2) We can be 90% confident that the proportion of Americans who choose not to go to college because they cannot afford it is contained within our confidence interval
(3) A survey should include at least 3002 people if we wanted the margin of error for the 90% confidence level to be about 1.5%.
Step-by-step explanation:
We are given that a simple random sample of 331 American adults who do not have a four-year college degree and are not currently enrolled in school, 48% said they decided not to go to college because they could not afford school.
Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;
P.Q. = [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of Americans who decide to not go to college = 48%
n = sample of American adults = 331
p = population proportion of Americans who decide to not go to
college because they cannot afford it
Here for constructing a 90% confidence interval we have used a One-sample z-test for proportions.
So, 90% confidence interval for the population proportion, p is ;
P(-1.645 < N(0,1) < 1.645) = 0.90 {As the critical value of z at 5% level
of significance are -1.645 & 1.645}
P(-1.645 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 1.645) = 0.90
P( [tex]-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]\hat p-p[/tex] < [tex]1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.90
P( [tex]\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.90
90% confidence interval for p = [ [tex]\hat p-1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+1.645 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]
= [ [tex]0.48 -1.96 \times {\sqrt{\frac{0.48(1-0.48)}{331} } }[/tex] , [tex]0.48 +1.96 \times {\sqrt{\frac{0.48(1-0.48)}{331} } }[/tex] ]
= [0.4348, 0.5252]
(1) Therefore, a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it is [0.4348, 0.5252].
(2) The interpretation of the above confidence interval is that we can be 90% confident that the proportion of Americans who choose not to go to college because they cannot afford it is contained within our confidence interval.
3) Now, it is given that we wanted the margin of error for the 90% confidence level to be about 1.5%.
So, the margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \sqrt{\frac{\hat p(1-\hat p)}{n} }[/tex]
[tex]0.015 = 1.645 \times \sqrt{\frac{0.48(1-0.48)}{n} }[/tex]
[tex]\sqrt{n} = \frac{1.645 \times \sqrt{0.48 \times 0.52} }{0.015}[/tex]
[tex]\sqrt{n}[/tex] = 54.79
n = [tex]54.79^{2}[/tex]
n = 3001.88 ≈ 3002
Hence, a survey should include at least 3002 people if we wanted the margin of error for the 90% confidence level to be about 1.5%.
The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 220 grams of a radioactive isotope, how much will be left after 5 half-lives?
Answer:
[tex]\boxed{6.875 \text{\: grams}}[/tex]
Step-by-step explanation:
Half-lives are how long it takes for half of a substance to decay. If you start with a certain amount and it decays for a certain amount of half-lives, you are dividing by [tex]2^{x}[/tex], where x is equal to the amount of half-lives.
In order to solve this question, simply divide the starting value by 2 raised to the value of half-lives.
[tex]\large\boxed{\frac{220}{2^{5}}=6.875\text{\: grams}}[/tex]
Please help me!!Which of the following functions shows the linear parent function, Fx) = X,
shifted right?
5
F(x) = x
5
A. G(x) = x + 2
B. G(x) = 4x
C. G(x) = x - 9
D. G(x) = -x
Answer:
C. G(x) = x - 9
Step-by-step explanation:
You know that the transformation ...
g(x) = f(x -h) +k
causes parent function f(x) to be shifted right h units and up k units.
You're looking for a function that is shifted right, so you want something that looks like ...
g(x) = f(x -constant) = x - constant
Choice C has that form:
C. G(x) = x - 9
_____
A. the function is shifted up 2 units
B. the function is vertically expanded by a factor of 4 (no shift)
C. shifted right
D. the function is reflected over the y-axis (no shift)
Answer: C [G(x) = x-9]
Step-by-step explanation:
I got it right
In a survey of 15000 students of different schools, 40% of them were found to have tuition before the see examination. Among them 50% studied only mathematics ,30% only science and 10% studied others subject. how many student studied mathematics as well as science.
Answer:
600
Step-by-step explanation:
first, 40% of 15000 is 6000,
10% of 6000, which is the number of students studying mathematics as well as science, 600
Answer:
•600 students studied both the subject.
Evaluate a + b for a = 12 and b = 6.
Answer:
Here,
a= 12
b = 6
Then,
a+b
= 12 + 6
= 18
.°. 18 is the solution
Answer:
[tex] \boxed{ \bold{ \boxed{ \sf{18}}}}[/tex]
Step-by-step explanation:
If the values of variables of algebraic expressions are given, the value of the term or expression can easily obtained by replacing the variables with numbers.
Given, a = 12 and b = 6
[tex] \sf{a + b}[/tex]
plug the values
⇒[tex] \sf{12 + 6}[/tex]
Add the numbers
⇒[tex] \sf{18}[/tex]
Hope I helped!
Best regards!!
John painted his most famous work, in his country, in 1930 on composition board with perimeter 101.14 in. If the rectangular painting is 5.43 in. taller than it is wide, find the dimensions of the painting.
Answer:
22.57 x 28
Step-by-step explanation:
10.86 + 4x = 101.14
-10.86 -10.86
4x = 90.28
/4 /4
x = 22.57
5.43 + 22.57 = 28
22.57
for the first one the answer are
add 5 to both sides
subtract 5 from both sides
add 1/2x to both sides
subtract 1/2 from both sides
the second one is
multiply both sides by 1/5
dived both sides by 1/5
multiply both sides by 6/7
dived both sides by 6/7
Answer:
1. add 1/2x to both sides
a. you want to combine the like terms. in this case, it is the x variable.
you are left with 7/6x = 5
2. multiply by 6/7
a. the reciprocal of 7/6 will cancel out the values
Kent Co. manufactures a product that sells for $60.00. Fixed costs are $285,000 and variable costs are $35.00 per unit. Kent can buy a new production machine that will increase fixed costs by $15,900 per year, but will decrease variable costs by $4.50 per unit. What effect would the purchase of the new machine have on Kent's break-even point in units?
0riginal break even point:
285000/ 60/35 = $166,250
New break even point = new fixed costs / ( selling price - variable cost/ selling price)
New break even point = 285,000 + 15,900. / ( 60-( 35-4.50)/60
300,900 / 60-30.50/60 = $612,000
The new break even point increases.
From a group of 11 people, 4 are randomly selected. What is the probability the 4 oldest people in the group were selected
The probability that the 4 oldest people in the group were selected is based on combinatorics is 0.00303 or 0.303%.
Given that:
Find how many ways the 4 oldest people can be selected from the group.
Since the 4 oldest people are already determined, there is only 1 way to select them.
n = 11 (total number of people in the group) and k = 4 (number of people to be selected).To calculate the probability, to determine the total number of ways to select 4 people from the group of 11. This can be found using the combination formula:
Number of ways to choose k items from n items :
C(n,k) = n! / (k!(n-k)!)
Calculate the total number of ways to select 4 people from the group:
Plugging n and k value from given data:
C(11,4 )= 11! / (4!(11-4)!)
On simplifications gives:
C(11, 4) = 330.
Calculate the probability:
Probability = Number of ways 4 oldest people selected / Total number of ways to select 4 people
Plugging the given data:
Probability = 1 / 330
Probability ≈ 0.00303 or 0.303%.
Therefore, the probability that the 4 oldest people in the group were selected is based on combinatorics is 0.00303 or 0.303%.
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Multiple Choice The opposite of –4 is A. 4. B. –4. C. –(–(–4)). D. –|4|.
Answer:
a. 4
Step-by-step explanation:
-1(-4) = 4
Answer:
A 4
Step-by-step explanation:
opposite of –4 = 4
A rectangle has an area of 81 square centimeters. Which of the following would be the rectangle's length and width? (Area = equals length×times width)
Answer:
length: 9cm
width: 9cm
Step-by-step explanation:
9×9=81
Will give brainliest. A farmer is painting a new barn. He will need to calculate the surface area of the barn to purchase the correct amount of paint. In which of the following units can the farmer expect to calculate the surface area? yd2 yd m3 m
Answer:
yd^2
Step-by-step explanation:
I took the test :)
The farmer calculate surface area in unit of [tex]yd^{2}[/tex]
Surface area :The surface area of any given object is the area or region occupied by the surface of the object.
Volume is the amount of space available in an object. Each shape has its surface area as well as volume.Surface area is the total area of the faces of a three-dimensional shape. Surface area is measured in square units.Thus , The farmer calculate surface area in unit of [tex]yd^{2}[/tex]
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The cost of performance tickets and beverages for a family of four can be modeled using the equation 4x+12=48,where x represents the cost of a. Ticket.how much is one ticket
Answer:
x=9; one ticket is $9
Step-by-step explanation:
4x+12=48
4x=48-12
4x=36
x=36/4
x=9
the height of a soccer ball that is kicked from the ground can be approximated by the function:
y = -12x^2 + 60x
where y is the height of the soccer ball in feet in x seconds after it is kicked. Find the time, in seconds, it takes from the moment soccer is kicked until it returns to the ground
Answer:
5 seconds
Step-by-step explanation:
Well we know that when the soccer ball is on the ground the height will be 0.
So we replace y with 0 and solve for x.
0=-12x²+60x
factor out and divide x, (this x is x=0, which is before he kicked it)
0=-12x+60
subtract 60 from both sides
-60=-12x
x=5
10. (01.02)
Given the function f(x)
3x - 4
5
which of the below expressions is correct? (1 point)
5x+4
f-1(x) =
3
f-1(x)
5x - 4
3
O f-'(x)
-344
-3x – 4
5
4–3x
f-1(x) =
5
Answer:
5x+4f-1(x)=3 this is short answer
Factor by grouping cd-9d-4c+36
Answer:
(d-4)(c-9)
Step-by-step explanation:
cd-9d-4c+36
d(c-9)-4(c-9)
pull out the (c-9),
(d-4)(c-9)
If the average fixed cost (AFC) of producing 5 bags of rice is $20.00, the average fixed cost of producing 10 bags will be
Answer:$40.00
Step-by-step explanation:first divide 20 by 5 and the answer will be 4. now multiply 10 into 4 and you'll get the answer $40.00
[tex]f(x) = sqr root x+3 ; g(x) = 8x - 7[/tex]
Find (f(g(x))
[tex]f(x)=\sqrt{x+3}\\g(x)=8x-7\\\\f(g(x))=\sqrt{8x-7+3}=\sqrt{8x-4}[/tex]
Pls help me I promise I’ll mark u brainleiest if I type in the fastest answer
Answer:
1. $-50
2. $25
Step-by-step explanation:
1. If she had $150 in her bank account and bought a bike for $200, then that means she spent all of her money PLUS $50 extra then what she had. That means $200-$150=$50. Her $150 is spent and that $50 becomes negative because she paid $200 when she only had $150.
2. If she deposits $75 in her account then it will be $75+(-50). That translates to $75-$50 which is $25.
+ and - = -
+ and + = +
- and - = +
Answer:
1. $-50
2. $25
Step-by-step explanation:
1.
We know that Clare originally had $150 in her account. She then buys a bike, which means she must have taken money out of her account for this purchase.
Since she spent $200, we need to subtract 200 from 150:
150 - 200 = -50
So, her account balance is $-50.
2.
Clare earns $75 later, which means she's receiving the money and can add it back into her account. Her current balance is -50, so we add 75 to -50:
-50 + 75 = $25
Thus, her account balance is now $25.
~ an aesthetics lover
Ernie Rolph borrowed $6700 at 4% annual simple interest. If exactly 1 year later he was able to repay the loan without penalty, how much interest would he owe? Ernie will owe $___ in interest.
Ernie will owe an interest of $268
What is the solution set for StartAbsoluteValue z + 4 EndAbsoluteValue greater-than 15? 11 less-than z less-than 19 Negative 19 less than z less-than 11 z less-than negative 19 or z greater-than 11 z less-than 19 or z greater-than 11
Answer:
z less-than negative 19 or z greater-than 11Step-by-step explanation:
Given the inequality [tex]|z+4|>15[/tex], we are to find the solution set of the inequality. Since the the function is an absolute value, this means that the function will be positive and negative.
For the positive value of the function;
[tex]z+4>15\\\\subtract\ 4\ from \ both \ sides\\z+4-4 > 15 -4\\\\z>11[/tex]
For the negative value of the function we have;
[tex]-(z+4) > 15\\\\-z-4> 15\\add\ 4 \ to\ both \ sides\\\\-z-4+4> 15+4\\\\-z> 19\\\\[/tex]
Multiplying both sides of the inequality by -1 will change the sense of the inequality sign;'
[tex]-(-z)< -19\\\\z<-19[/tex]
Hence the solution sets are [tex]z> 11 \ and \ z< -19 \\[/tex] OR z less-than negative 19 or z greater-than 11
Answer:
z less-than negative 19 or z greater-than 11
Step-by-step explanation:
3y – 6x = 3 y = 2x + 1
Answer:
infinite solutions along the line y = 2x+1
Step-by-step explanation:
3y – 6x = 3
y = 2x + 1
Replace y in the first equation with the second equation
3 ( 2x+1) -6x =3
6x +3 -6x = 3
3=3
This is always true so there are infinite solutions along the line y = 2x+1
Step-by-step explanation:
Hi, there!!!
you mean to solve it, right.
then let's begin...
3y-6x=3..........epuation 1.
y = 2x+1..........equation 2.
now, substituting the value y of equation 2 in equation 1. so, we get,
3y-6x=3
or, 3(2x+1) -6x = 3
or, 6x+3-6x=3
by simplifying it we get, 3=3
so, this equation can have infinite solution.
you may have wrote wrong question ..
Solve for x and y simultaneous equations: 2x+y=10
-3x+y=-5
Step-by-step explanation:
Hey, there!
Given, equations are,
2x+y=10.............(i)
-3x+y= -5...........(ii)
From equation (i)
y=10- 2x...........(iii)
Putting the value of "y" from equation (iii) in equation (ii).
-3x+y= -5
-3x + (10-2x)= -5
-3x + 10-2x= -5
- 5x = -15
[tex]x = \frac{ - 15}{ - 5} [/tex]
Therefore, x= 3.
Now, putting the value of "x" in equation (iii).
y= 10- 2x
y= 10- 2×3
Therefore, y= 4.
Hope it helps...
In your own words, define Quadratic Equation. How many solutions does a Quadratic Equation have?
Answer: an equation that has one term which is nameless and squared also no term which gets raised to higher power.
Step-by-step explanation:
state if the triangles in each pair are similar. If so State how you know they are similar and complete the similarity statement
Answer:
fourth option
Step-by-step explanation:
∠ FTC = ∠ MTL ( vertical angles )
Since FC and ML are parallel, then
∠ FCT = ∠ TML (corresponding angles )
Thus
Δ TCF ~ Δ TML by the AA postulate
Answer:
[tex]\large \boxed{\mathrm{similar, \ AA \ similarity}, \ \Delta TML}[/tex]
Step-by-step explanation:
The two triangles are similar.
We can prove by angle-angle similarity, in [tex]\mathrm{AA}[/tex] similarity, there are two pairs of congruent corresponding angles in two triangles, this proves the two triangles are similar.
[tex]\angle U[/tex] and [tex]\angle M[/tex] are a pair of congruent corresponding angles.
[tex]\angle V[/tex] and [tex]\angle L[/tex] are a pair of congruent corresponding angles.
Therefore,
[tex]\Delta TUV \sim \Delta TML[/tex]
In tests of a computer component, it is found that the mean time between failures is 520 hours. A modification is made which is supposed to increase the time between failures. Tests on a random sample of 10 modified components resulted in the following times (in hours) between failures. 518 548 561 523 536 499 538 557 528 563 At the 0.05 significance level, test the claim that for the modified components, the mean time between failures is greater than 520 hours. Use the P-value method of testing hypotheses.
H0:
H1:
Test Statistic:
Critical Value:
Do you reject H0?
Conclusion:
If you were told that the p-value for the test statistic for this hypothesis test is 0.014, would you reach the same decision that you made for the Rejection of H0 and the conclusion as above?
Answer:
As the calculated value of t is greater than critical value reject H0. The tests supports the claim at ∝= 0.05
If the p-value for the test statistic for this hypothesis test is 0.014, then the critical region is t ( with df=9) for a right tailed test is 2.821
then we would accept H0. The test would not support the claim at ∝= 0.01
Step-by-step explanation:
Mean x`= 518 +548 +561 +523 + 536 + 499+ 538 + 557+ 528 +563 /10
x`= 537.1
The Variance is = 20.70
H0 μ≤ 520
Ha μ > 520
Significance level is set at ∝= 0.05
The critical region is t ( with df=9) for a right tailed test is 1.8331
The test statistic under H0 is
t=x`- x/ s/ √n
Which has t distribution with n-1 degrees of freedom which is equal to 9
t=x`- x/ s/ √n
t = 537.1- 520 / 20.7 / √10
t= 17.1 / 20.7/ 3.16227
t= 17.1/ 6.5459
t= 2.6122
As the calculated value of t is greater than critical value reject H0. The tests supports the claim at ∝= 0.05
If the p-value for the test statistic for this hypothesis test is 0.014, then the critical region is t ( with df=9) for a right tailed test is 2.821
then we would accept H0. The test would not support the claim at ∝= 0.01
Please help. I’ll mark you as brainliest if correct!
Answer:
9 3 -7 -13
4 -4 11 8
0 9 2 -4
Step-by-step explanation:
9 3 -7 -13
4 -4 11 8
0 9 2 -4
Answer: 9 3 -7 -13
4 -4 11 8
0 9 2 -4
Step-by-step explanation:
PLEASE ANSWER ASAP!!!
Melissa is able to Rollerblade 100 feet in 3.8 seconds. Calculate how fast she Rollerblade in miles per hour?
Answers options given will be in picture
any unrelated answer will be reported
Answer:
A
Step-by-step explanation:
100fps=68.182mph
68.182/3.8=17.94
Mellissa's speed will be 17.94 mph.
What is speed?Speed is defined as the ratio of the time distance travelled by the body to the time taken by the body to cover the distance.
It is given that Melissa is able to Rollerblade 100 feet in 3.8 seconds.
We know that 100fps is equal to 68.182mph.
Mellissa's speed in meters per hour is calculated as:-
S = 68.182/3.8=17.94mph
Therefore, Mellissa's speed will be 17.94 mph.
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