Answer:
cos2x=-17/145
Step-by-step explanation:
Recall cos2x=cos^2x-sin^2x
Or cos2x=cos^2x-(1-cos^2x)*
Or cos2x=2cos^2x-1**
*By a Pythagorean Identity
**Combined like terms
I'm going to use third identity from above because I only have to find cosx or cos^2x to get requested answer for cos2x.
Recall Pythagorean identity 1+tan^2x=sec^2x.
Plug in our tangent valuem...
1+(9/8)^2=sec^2x
1+81/64=sec^2x
145/64=sec^2x
Cosine and secant are reciprocals of each other.
64/145=cos^2x
Now we are ready to plug in and get final answer:
cos2x=2cos^2x-1
cos2x=2(64/145)-1
cos2x=128/145-1
cos2x=-17/145
Below, the two-way table is given for a
class of students.
Freshmen Sophomore
Juniors
Seniors
Total
Male
4
6
2
2
Female 3
4
6
3
Total
If a student is selected at random, find the
probability the student is a male given that it's
a sophomore. Round to the nearest whole
percent.
[?]%
Answer:
20%
Step-by-step explanation:
The total number of students is: 4 + 6 + 2 + 2 + 3 + 4 + 6 + 3 = 30 (students)
The probability is: 6/30 = 1/5 = 0.2 = 20%
The probability that the student is a male given that he's a sophomore is approximately 60%.
What is probability?It is the chance of an event to occur from a total number of outcomes.
The formula for probability is given as:
Probability = Number of required events / Total number of outcomes.
Example:
The probability of getting a head in tossing a coin.
P(H) = 1/2
We have,
The probability that the student is a male given that it's a sophomore can be calculated using the formula:
P(male | sophomore) = P(male and sophomore) / P(sophomore)
The number of male sophomores is 6, and the total number of sophomores is 6+4=10.
So, the probability of selecting a sophomore is:
P(sophomore)
= (number of sophomores) / (total number of students)
= 10 / 23
The number of male sophomores is 6.
So,
The probability of selecting a male sophomore is:
P(male and sophomore) = 6 / 23
Therefore,
The probability that the student is a male given that it's a sophomore is:
P(male | sophomore)
= (6 / 23) / (10 / 23)
= 6 / 10
= 3 / 5
Rounding to the nearest whole percent, we get:
P(male | sophomore) ≈ 60%
Thus,
The probability that the student is a male given that he's a sophomore is approximately 60%.
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I need help.
You are interested in finding a 95% confidence interval for the average commute that non-residential students have to their college. The data below show the number of commute miles for 12 randomly selected non-residential college students. Round answers to 3 decimal places where possible.
Answer:
(11.847 ; 15.813)
Step-by-step explanation:
We are given 12 samples which are :
8, 20, 20, 11, 18, 12, 6, 5, 7, 22, 12, 25
We use a T-distribution to find the confidence interval since the sample size. is small, n < 30
Using a calculator :
The sample mean, xbar = 13.83
Sample standard deviation, s = 6.87
The confidence interval, C.I
C.I = xbar ± Tcritical * s/√n)
Tcritical at 95%, df = n - 1, 12 - 1 = 11
Tcritical(0.05, 11) = 2.20
Hence,
C.I = 13.83 ± 2.20(6.87/√12)
C.I = 13.83 ± 1.9831981
C. I = (13.83 - 1.983 ; 13.83 + 1.983)
C. I = (11.847 ; 15.813)
The graph below shows a company's profit f(x), in dollars, depending on the price of pencils x, in dollars, sold by the company.
Part A: What do the x-intercepts and maximum value of the graph represent? What are the intervals where the function is increasing and decreasing, and what do they represent about the sale and profit? (4 points)
Part B: What is an approximate average rate of change of the graph from x = 2 to x = 5, and what does this rate represent? (3 points)
Part C: Describe the constraints of the domain. (3 points)
Answer:
Step-by-step explanation:
Part A
The x-intercept are the values of the variable "x" for which the value of the function, f(x) is zero (f(x) = 0)
The given parameters are;
The values of the function, f(x) = The company's profit
The values of the independent variable, "x" = The price of erasers
Therefore, at the x-intercept, where the values of the variable "x" are 0 and 8, the profit of the company, (f(x)) is 0 (the company does not make any profit)
2) The maximum value, which is the highest point of the graph with coordinate (4, 270), gives the company's maximum profit, f(x) = $270, and the price of the eraser, x-value, at which the company makes maximum profit which is at the price of an eraser, x = $4
3) The intervals where the function is increasing is 0 ≤ x ≤ 4
At the interval where the function is increasing, the sale price is increasing and the profits are increasing
The intervals where the function is decreasing is 4 ≤ x ≤ 8
At the interval where the function is decreasing, the sale price is increasing and the profits are decreasing
Part B
The appropriate average rate of change of the graph from x = 1 to x = 4 where f(x) = 120 and 270 respectively is given as follows
Rate of change of the graph from x = 1 to x = 4 is (270 -120)/(4 - 1) = 50
The average rate of change of the graph represents that the as the price of the eraser increases by $1.00 the profits increases by $50.00
THIS WAS NOT MY OWN ANSWER, PLEASE LET oeerivona TAKE THE POINTS!!
Matthew Travels 42/50 Meters In 26/30 Minutes. Find The Speed of Mathew In Meters Per Second.
Answer:
Matthew travels 0.0161 meters per second.
Step-by-step explanation:
Given that Matthew travels 42/50 meters In 26/30 minutes, to find the speed of Mathew in meters per second the following calculation must be performed:
42/50 = 0.84
26/30 = 0.86
0.86 x 60 = 52
0.84 meters in 52 seconds
0.84 / 52 = 0.01615
Therefore, Matthew travels 0.0161 meters per second.
HELP ASAP!!!!!!!PLEASE SHOW WORK!!!!!!
Answer:
Area = 72.62 m²
Step-by-step explanation:
Area of a triangle with the given three sides is given by,
Area = [tex]\sqrt{s(s-a)(s-b)(s-c)}[/tex]
Here, s = [tex]\frac{a+b+c}{2}[/tex]
And a, b, c are the sides of the triangle.
From the question,
a = 20 m, b = 10 m and c = 15 m
s = [tex]\frac{20+10+15}{2}[/tex]
s = 22.5
Substitute these values in the formula,
Area = [tex]\sqrt{22.5(22.5-20)(22.5-10)(22.5-15)}[/tex]
= [tex]\sqrt{22.5(2.5)(12.5)(7.5)}[/tex]
= [tex]\sqrt{5273.4375}[/tex]
= 72.62 m²
From a random sample of 20 bars selected at random from those produced, calculations gave a mean weight of = 52.46 grams and standard deviation of s = 0.42 grams. Assuming t distribution is followed, construct a 90% confidence interval for the mean weight of bars produced, giving the limits to two decimal places.
Answer:
(52.30 ; 52.62)
Step-by-step explanation:
Given :
Sample size, n = 20
Mean, xbar = 52.46
Standard deviation, s = 0.42
We assume a t - distribution
The 90% confidence interval
The confidence interval relation :
C.I = xbar ± Tcritical * s/√n
To obtain the Tcritical value :
Degree of freedom, df = n - 1 ; 20 - 1 = 19 ; α = (1 - 0.90) /2 = 0.1/2 = 0.05
Using the T-distribution table, Tcritical = 1.729
We now have :
C.I = 52.46 ± (1.729 * 0.42/√20)
C. I = 52.46 ± 0.1624
C.I = (52.30 ; 52.62)
The global surface water area is 361, 132,000 square metres. Calculate the volume of water needed to cause a 3mm in sea level.
Answer:
The volume of water is 396 cubic meter.
Step-by-step explanation:
Area of water, A = 132000 square meter
Height, h = 3 mm = 0.003 m
The volume of water is given by
V = Area x height
V = 132000 x 0.003
V = 396 cubic meter.
5. A Ferris wheel at an amusement park measures 16m in diameter. It makes 3 rotations
every minute. The bottom of the Ferris wheel is 1m above the ground. Riders board the
Ferris wheel at the minimum point.
a) Determine the equation that models Emily's height (m) with respect to time (in seconds)
above ground. [3A]
b) A 12m tree stands near the Ferris wheel. For how long (in seconds) is Emily higher than
the tree during the first rotation? Round to 2 decimal places. [4A]
Following are the responses to the given points:
For point a:
[tex]Diameter\ (d)= 16\ m\\\\[/tex]
Calculating the 3 rotations for every minute:
Calculating time for completing 1 rotation:
[tex]1\ rotation=\frac{60}{3}= 20\ second\\\\period=20 \ second\\\\[/tex]
The standard form of the equation of the sine and cosine function is:
[tex]y=A \sin \{ B(x-c)\} +D\\\\y=A \cos \{ B(x-c)\} +D\\\\[/tex]
Calculating the Amplitue:
[tex]A=\frac{max-min}{2}=\frac{17-1}{2}=\frac{16}{2}=8\\\\Period=\frac{2\pi}{B}\\\\20=\frac{2\pi}{B}\\\\B=\frac{2\pi}{20}\\\\B=\frac{\pi}{10}\\\\[/tex]
Calculating the phase shift:
for [tex]\sin[/tex] function: [tex]c=5[/tex]
for [tex]\cos[/tex] function: [tex]c=10[/tex]
Calculating the vertical shift:
[tex]\to D=\frac{max+ min }{2}=\frac{17+ 1}{2}=\frac{18}{2}=9\\\\y=8 \sin \{ \frac{\pi}{10}(t-5)\} +9\\\\y=8 \cos \{ \frac{\pi}{10}(t-10)\} +9\\\\[/tex]
For point b:
[tex]y> 12\ m\\\\12=8 \sin \{ \frac{\pi}{10}(t-5)\} +9\\\\12-9=8 \sin \{ \frac{\pi}{10}(t-5)\} \\\\3=8 \sin \{ \frac{\pi}{10}(t-5)\} \\\\\frac{3}{8}=\sin \{ \frac{\pi}{10}(t-5)\} \\\\\sin^{-1}\frac{3}{8}=\frac{\pi}{10}(t-5) \\\\\frac{\pi}{10} (0.38439677)=(t-5) \\\\1.22357+5=t \\\\t=6.22357\ second\\\\t=6.22\ second\\\\\sin^{-1}\frac{3}{8}=\frac{\pi}{10}(t-5) \\\\\frac{\pi}{10} (2.7571961)=(t-5) \\\\t=8.7764+5\\\\t=13.78\ second\\\\t_2-t_1=13.7764-6.22357= 7.55283\approx 7.55\ second \\\\[/tex]
Learn more:
Rotation: brainly.in/question/39626227
Find X?
please help?
Look at one side of the triangle. It forms a right triangle with 45 degree angles.
A 45 degree triangle the base and height are the same, so the height would also be 26.
The hypotenuse(x) of a 45 degree right triangle is the side length time the sqrt(2)
The answer is: 26 sqrt(2)
Which ratio expresses the scale used to create this drawing?
1 square=10 yards
Answer:
option B
Step-by-step explanation:
option B
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Someone help me pls !!!!!
Answer:
1)a
the problem asks"what PERCENT of 5 is 4?"
2)part
it gives both the percent and the whole, so your left with the part
3)Whole
4 is a part which is 80%
Step-by-step explanation:
A television stand at Wiles' Discount Mart is $187, and the sales tax is 6%. What is the amount of tax to be paid for the TV?
Answer:
$11.22
Step-by-step explanation:
100% = 187
1% = 187/100 = $1.87
6% = 1%×6 = 1.87×6 = $11.22
Answer:
In this case, you need to calculate the 6% of the price, which is 187 $.
We only need to multiply the price (187) by the percentage (6%):
187 * 0.06 = 11.22
So the tax would be $11.22
PLEASE i need the answers!!!!!!!!!
I have no time please if you know the answer please tell MEEE!!!!!!!!!!!
Answer:
5x^2(2-3x)
(n+4)(x+y)
Step-by-step explanation:
A new restaurant sells cheeseburgers for 6$, french fries for 3$, and salads for 8$ On opening night, the restaurant sold items and made 1070$. They sold 4 times as many fries as salads. How many cheeseburgers were sold?
Answer:
25 cheeseburger
Step-by-step explanation:
I checked and get that 4 times fries as many as salad means that fries = 4 times Salad.
Brainliest please~
25 cheeseburgers were sold.
What is algebraic expression?In mathematics, an expression that incorporates variables, constants, and algebraic operations is known as an algebraic expression (addition, subtraction, etc.). Terms comprise expressions.
Let cheeseburger be x
Price of x = 6
Let French Fries be y
Price of y = 3
Let salads be z
Price of z=8
x+ y+ z =220
6x + 3y + 8z = 1070
4 y = z 4 times as many as
= 4 times - Fries is more than Salad
Substitute 3 in 1
x + 4 z + z =220
x+5z =220
Substitute 3 in 2
6x + 12z +8z = 1070
6x + 20z = 1070
3x + 10z - 535
From 4: x=220-5z
Substitute into 3 (220-5z) +10z = 535
660 - 15z+10z=535
- 5z = - 125
z = 25
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4, 1 and 0, -4 on a graph
Answer:
Hope this will help.
Halp me please. This questions is killing me. I need the answer. Solve $3a + 4b = a - 8b + 24$ for $a$ in terms of $b$.
Answer:
a=12-6b
Step-by-step explanation:
move b and a to their respective sides, getting a = -6b+12
tada :)
As per linear equation, the value of 'a' in terms of 'b' will be
a = 12 - 6b.
What is a linear equation?A linear equation is an equation that has one or multiple variables with the highest power of the variable is 1.
Given, (3a + 4b) = (a - 8b + 24)
⇒ 3a - a = - 8b + 24 - 4b
⇒ 2a = - 12b + 24
⇒ a = (- 12b + 24)/2
⇒ a = - 6b + 12
⇒ a = 12 - 6b
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In a recent health survey, 333 adult respondents reported a history of diabetes out of 3573 respondents. What is the critical value for a 90% confidence interval of the proportion of respondents who reported a history of diabetes
Answer:
The critical value for the 90% confidence interval is [tex]Z_c = 1.645[/tex].
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
The critical value for the 90% confidence interval is [tex]Z_c = 1.645[/tex].
The length of a rectangle is 7cm less than 3 times it's width. It's area is 20 square cm. Find the dimensions of the rectangle
Answer:
4 cm by 5 cm (4 x 5)
Step-by-step explanation:
The area of a rectangle with length [tex]l[/tex] and width [tex]w[/tex] is given by [tex]A=lw[/tex]. Since the length of the rectangle is 7 less than 3 times its width, we can write the length as [tex]3w-7[/tex]. Therefore, substitute [tex]l=3w-7[/tex] into [tex]A=lw[/tex]:
[tex]A=lw,\\20=(3w-7)w[/tex]
Distribute:
[tex]20=3w^2-7w[/tex]
Subtract 20 from both sides:
[tex]3w^2-7w-20=0[/tex]
Factor:
[tex](w-4)(3w+5)=0,\\\begin{cases}w-4=0, w=\boxed{4},\\3w+5=0, 3w=-5, w=\boxed{-\frac{5}{3}}\end{cases}[/tex]
Since [tex]w=-\frac{5}{3}[/tex] is extraneous (our dimensions cannot be negative), our answer is [tex]w=4[/tex]. Thus, the length must be [tex]20=4l, l=\frac{20}{4}=\boxed{5}[/tex] and the dimension of the rectangle are 4 cm by 5 cm (4 x 5).
Can someone please do these three and number them? -Numbers: 10,11,12-
Answer:
10. Option: c11. Option: a12. Option: aDoes anyone know these?
Answer:
1 = - 4 - 14 √3
2 = 9 - 11 √3
Step-by-step explanation:
Question 1
(-4√3 + 2)(√3 + 4)
Apply FOIL method
= (-4√3) √3 + (-4√3) . 4 + 2 √3 + 2 . 4
Apply minus-plus rules: + (-a) = -a
= -4 √3 √3 - 4 . 4 √3 + 2 √3 + 2 . 4
Simplify
= - 4 - 14 √3
Question 2
(-3 + √3)(1 + 4 √3)
Apply FOIL method
= (-3) . 1 + (-3) . 4 √3 + √3 . 1 + √3 . 4 √3
Apply minus-plus rules: + (-a) = -a
= -3 . 1 - 3 . 4 √3 + 1 . √3 + 4 √3 √3
Simplify
= 9 - 11 √3
20 students were asked “How many pets do you have in your household?” and the following data was collected:
2 1 0 3 1 2 1 3 4 0
0 2 2 0 1 1 0 1 0 1
Select the type of the data ?
Discrete
Continuous
Categorical
Qualitative
NO FAKE ANS
FRIST MARKED BRAINLIST
CHOOSE ONE ANS
Answer:
qualitative
Step-by-step explanation:
bcos the question is in quality format
Answer:
we are armysss!!!!\
hiiiiiiiiii
yoooooooo
heyyyyyy
brainlist meeee!
Urgent need answer for this one.
Answer:
4th option
Step-by-step explanation:
6/sin(65) = 5/sin(x)
or, 6×sin(x) = 5×sin(65)
or, sin(x) = 5×sin(65)/6
or, x = arcsin(5×sin(65)/6)
what is the relationship and what does X equal?
help! :)
Answer:
4x + 3 = 59
x = 14
Step-by-step explanation:
The vertical angles theorem states that when two lines intersect, the angles opposite each other are congruent. One can apply this here by stating the following:
4x + 3 = 59
Solve for (x), use inverse oeprations:
4x + 3= 59
4x = 56
x = 14
Answer:
Relationship : Vertical angle
Step-by-step explanation:
(4x + 3) = 59
4x = 59 - 3
4x = 56
x = 56/4
x = 14
Three ounces of cinnamon cost $2.40. If there are 16 ounces in 1 pound, how much does cinnamon cost per pound?
annual cost of 35,000 expected to save 40,000 during the first year how many months will the take to recover investment
Answer:
500000
Step-by-step explanation:
find m∠H
What does m∠H happened to equal
Answer:
[tex]m\angle H = 30^o[/tex]
Step-by-step explanation:
Given
See attachment
Required
Find [tex]m\angle H[/tex]
To calculate [tex]m\angle H[/tex], we make use of:
[tex]\cos(\theta) = \frac{Adjacent}{Hypotenuse}[/tex]
So, we have:
[tex]\cos(H) = \frac{GH}{HI}[/tex]
This gives:
[tex]\cos(H) = \frac{10\sqrt3}{20}[/tex]
[tex]\cos(H) = \frac{\sqrt3}{2}[/tex]
Take arccos of both sides
[tex]m\angle H = cos^{-1}(\frac{\sqrt3}{2})[/tex]
[tex]m\angle H = 30^o[/tex]
What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4?
1
–1
i
–i
Answer:
Answer is -1
Step-by-step explanation:
i1 = i
i2 = -1
i3 = -i
i4 = 1
i0 × i1 × i2 × i3 × i4 = 1 × i × (- 1) × (- i) × 1 = i2 = - 1
Answer:the answer is -1
Step-by-step explanation:
Norman and Suzanne own 35 shares of a fast food restaurant stock and 63 shares of a toy company stock. At the close of the markets on a particular day in 2004, their stock portfolio consisting of these two stocks was worth $1596.00. The closing price of the fast food restaurant stock was $19 more per share than the closing price of the toy company stock on that day. What was the closing price of each stock on that day? The price per share of the fast food restaurant stock is
Answer:
closing price of the fast food stock was $997.50
closing price of the toy company stock was $598.50
the price per fast food share was $28.50
Step-by-step explanation:
x = price per share fast food
y = price per share toy company
35x + 63y = 1596
x = y + 19
=>
35(y+19) + 63y = 1596
35y + 665 + 63y = 1596
98y + 665 = 1596
98y = 931
y = $9.50
=>
x = 9.5 + 19 = $28.50
the value of the whole fast food stock was
35x = 35×28.5 = $997.50
the cake if the whole toy company stock was
63y = 63×9.5 = $598.50
A certain brand of coffee comes in two sizes. An 11.5-ounce package costs $.4.24 . A 27.8-ounce package costs $9.98.
Find the unit price for each size. Then state which size is the better buy based on the unit price.
Round your answers to the nearest cent.
Answer:
Small (11.5) is 37 cents per ounce.
Large (27.8) is 36 cents per ounce.
27.8 ounces is the better buy.
The theoretical mean of a distribution is also known as its ______________.
Answer:
skewness
Step-by-step explanation:
Average.
The average of a set of observations is the most important and useful measure of statistics and is a position measure, as it shows the positions of the numbers to which it refers. The average value is involved in several types of statistics and is examined in almost all statistical distributions. It is generally defined as the sum of the observations by their number. That is, it is the mathematical operation of finding the "mean distance" between two or more numbers.
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