Answer:
The 95% confidence interval for the population mean of such waiting times is between 19.5 and 24.5 minutes. This means that we are 95% sure that the true mean waiting time of all calls for this company is between 19.5 and 24.5 minutes.
The 99% confidence interval for the population mean of such waiting times is between 18.6 and 25.4 minutes. This means that we are 99% sure that the true mean waiting time of all calls for this company is between 18.6 and 25.4 minutes.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 25 - 1 = 24
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0639
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.0639\frac{6}{\sqrt{25}} = 2.5[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 22 - 2.5 = 19.5 minutes
The upper end of the interval is the sample mean added to M. So it is 22 + 2.5 = 24.5 minutes
The 95% confidence interval for the population mean of such waiting times is between 19.5 and 24.5 minutes. This means that we are 95% sure that the true mean waiting time of all calls for this company is between 19.5 and 24.5 minutes.
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995[/tex]. So we have T = 2.797
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.797\frac{6}{\sqrt{25}} = 3.4[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 22 - 3.4 = 18.6 minutes
The upper end of the interval is the sample mean added to M. So it is 22 + 3.4 = 25.4 minutes
The 99% confidence interval for the population mean of such waiting times is between 18.6 and 25.4 minutes. This means that we are 99% sure that the true mean waiting time of all calls for this company is between 18.6 and 25.4 minutes.
A rocket is fired upward with an initial velocity v of 100 meters per second. The quadratic function S(t)=-5t^2+100t can be used to find the height s of the rocket, in meters, at any time t in seconds. Find the height of the rocket 7 seconds after it takes off. During the course of its flight, after how many seconds will the rocket be at a height of 450 meters?
The rocket will be at the height of 450metres at 13.16secs and 6.84secs
Given the expression modeled by the height S(t)=-5t^2+100t where
t is the time taken by the rocket to take off
s is the height traveled by rocket
In order to find the height of the rocket 7 seconds after it takes off, we will substitute t = 7 into the equation
S(7) = -5(7)²+100(7)
S(7) = -5(49)+700
S(7) = -245+700
S(7) = 455metres
Hence the height of the rocket 7 seconds after it takes off is 455metres
Given that S = 450m, we can also get the time taken by the rocket at this height.
Recall that S(t)= -5t²+100t
450 = -5t²+100t
Rearrange
-5t²+100t - 450 = 0
5t²-100t + 450 = 0
Divide through by 5
t²-20t + 90 = 0
On factorizing above equation;
t= 10+√10 or t=10−√10
t = 10+3.1623 or 10 - 3.1623
t = 13.16 and 6.84secs
Hence the rocket will be at the height of 450metres at 13.16secs and 6.84secs
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Jacob bought a magazine for $2.80 and three candy bars. Write an expression for how much Jacob paid.
Answer:
total = 2.8 + 3x
x is the price of the candy bars
Evaluate 6 x (15 - 7) - 4
A: 10
B: 24
C: 44
D: 79
Answer:
44
Step-by-step explanation:
6 x (15 - 7) - 4
PEMDAS says Parentheses first
6 x (8) - 4
Then multiply
48 -4
Then subtract
44
One number is eight less than a second number. Five times the first is 6 more than 6 times the second. Find the numbers. The value of the first number is _____.
Answer:
I think the value of first number is 30.
HELP!!!!
Please help me!!
I need help!!
HELP!!!!
Answer:
Pretty sure it's A
Step-by-step explanation:
The x outside the parenthesis means that there's an x intercept at (0,0) and (x-3) means there's another one at (3,0)
A region is bounded by x=y^2 and x=4 and y=0 and revolved about the line x=5. Find the volume using shell method.
If you draw the bounded region in the x,y-plane, you'll find it to be somewhat ambiguous, but since y = 0 cuts the area between the parabola x = y ² and x = 4 perfectly in half, you can use either the top or bottom half. I'll use the top one, i.e. assume y ≥ 0.
For every x taken from the interval [0, 4], we can get a shell with height √x. The distance from x to the axis of revolution, x = 5, is 5 - x, which corresponds to the radius of the shell. The area of this shell is
2π (radius) (height) = 2π (5 - x) √x
Then the volume of the solid is the sum of infinitely many such shells made at every 0 ≤ x ≤ 4, given by the integral
[tex]\displaystyle 2\pi \int_0^4 (5-x)\sqrt x\,\mathrm dx = 2\pi \int_0^4 \left(5x^{1/2}-x^{3/2}\right)\,\mathrm dx \\\\ = 2\pi \left(\frac{10}3x^{3/2}-\frac25x^{5/2}\right)\bigg|_0^4 \\\\ = \boxed{\frac{416\pi}{15}}[/tex]
The graph shown below expresses a radical function that can be written in
17
the form f(x) = a(x + k)!
C. What does the graph tell you about the
value of k in this function
Answer:
C. [tex]k[/tex] is greater than zero.
Step-by-step explanation:
We know that graph is obtained from the function of the form [tex]f(x) = a\cdot (x+k)^{1/n} + c[/tex]. According to the graph and if [tex]x + k = 0[/tex], we find that:
[tex]x = -k[/tex] (1)
[tex]x < 0[/tex] (2)
By (1) and (2):
[tex]-k < 0[/tex]
[tex]k > 0[/tex]
Hence, correct answer is C.
Find the value of x.
A. 6
B. 3
C. 5
D. 2
[tex]\\ \sf\longmapsto \dfrac{AK}{DK}=\dfrac{CK}{BK}[/tex]
[tex]\\ \sf\longmapsto \dfrac{14}{12}=\dfrac{4x+1}{3x+3}[/tex]
[tex]\\ \sf\longmapsto \dfrac{7}{6}=\dfrac{4x+1}{3x+3}[/tex]
[tex]\\ \sf\longmapsto 7(3x+3)=6(4x+1)[/tex]
[tex]\\ \sf\longmapsto 21x+21=24x+6[/tex]
[tex]\\ \sf\longmapsto 24x-21x=21-6[/tex]
[tex]\\ \sf\longmapsto 3x=15[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{15}{3}[/tex]
[tex]\\ \sf\longmapsto x=5[/tex]
Need help with precalc please! Thank you!
que es eso ._ .wooooooooo .
What are the values of (-2)4 and -24?
1. 8 and -8
2. -8 and -8
3. 16 and -16
4. 16 and 16
Answer:
2.
Step-by-step explanation:
(-2)×4=-8
-2×4=-8
~~~~~~~~
Answer:
16 and 16 is the correct answer
Consider the generic chemical equation:
2 A + 3 B ------> 3 C
If 6 moles of A and 2 moles of B are reacted, what is the maximum number of moles of C that can be formed?
For this problem, you can see that a ratio exists between A, B, and C. Now you'll just have to find the constant k that satisfies this ratio using the proportional relationship formula.
After that, you can plug in the constant k to find the missing C value.
I will give a brainliest and 20pts to the person that can use the Pythagorean theorem to solve for x. Please help. I went over it several times and the answer I got doesn't match up with what the box says
Answer:
x = 48
Step-by-step explanation:
Pythagorean thm:
a² + b² = c²
Given:
a = x
b = 36
c = 60
Work:
a² + b² = c²
x² + 36² = 60²
x² + 1296 = 3600
x² = 3600 - 1296
x² = 2304
√x² = √2304
x = 48
Carlos is an administrative assistant at an insurance agency. He wants to gather feedback from customers on their service. He doesn't have a lot of time, and he wants to have some data to share with his supervisor. What is the best way for Carlos to gather feedback? O a) Individual interviews O b) Survey O c) Focus group d) Phone calls
Answer: b) Surveys
When a person does not have enough time he must should take the faster and effective route in this case carlos does not have time for individual interviews or phone calls. Focus group is not used to get feedback it is to discuss about data before a item is launched. Therefore it should be survey because it is used to collect feedback from large amount of people.
Must click thanks and mark brainliest
A wall that is 10 feet high and 16 feet wide is to be painted, but the wall has two rectangular windows (which should not be painted). If each window is 4 feet by 7 feet, determine the area of the space to be painted.
Answer:
104 square feet
Step-by-step explanation:
Total area of the wall: 10 x 16 = 160 square feet
Area of each window: 4 x 7 = 28
Since there are 2 windows, the total area that should not be painted is 28 x 2 = 56 square feet
160 - 56 = 104 square feet
To determine the area of the space to be painted on a wall with two rectangular windows, we need to calculate the total area of the wall and subtract the area of the windows.
First, let's calculate the area of the wall. The wall is 10 feet high and 16 feet wide, so the total area of the wall is: Area of wall = height × width = 10 feet × 16 feet = 160 square feet Next, let's calculate the area of each window. Each window is 4 feet high and 7 feet wide, so the area of each window is: Area of window [tex]= height × width = 4 feet × 7 feet = 28[/tex] square feet Since there are two windows, the total area covered by the windows is 2 times the area of one window,
Which is: Total area of windows [tex]= 2 × 28[/tex] square feet = 56 square feet Finally, we can calculate the area of the space to be painted by subtracting the total area covered by the windows from the total area of the wall: Area to be painted = Area of wall - Total area of windows = 160 square feet - 56 square feet = 104 square feet Therefore, the area of the space to be painted on the wall is 104 square feet.
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Ginny and her classmates formed a study group. The number of girls in the study group was 3 more than twice the number
of boys. There were 11 girls in the study group. How many boys were in the study group?
Answer:
I think the answer is 4 boys
Step-by-step explanation:
Let the no of boys be y.
No. of girls = 11
= 3 + 2y (equation)
3 + 2y = 11
3 - 3 + 2y = 11 - 3
2y = 8
2y/2 = 8/2
y = 4
Boys = 4
Solve
0.9(7x + 14) = 1.5 - (x + 2)
[tex]\\ \sf\longmapsto 0.9(7x+14)=1.5-(x+2)[/tex]
[tex]\\ \sf\longmapsto 6.3x+12.6=1.5-x-2[/tex]
[tex]\\ \sf\longmapsto 63x+12.6=-x-0.5[/tex]
[tex]\\ \sf\longmapsto 63x+x=-0.5-12.6[/tex]
[tex]\\ \sf\longmapsto 64x=-13.1[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{-13.1}{64}[/tex]
[tex]\\ \sf\longmapsto x=0.2[/tex]
Use the following graph to evaluate f’(-5) and f’(-1).
Answer:
Bonsoir,
f'(-5)=-4/3
f'(-1) =3/4
Step-by-step explanation:
f'(-5) = ?
2 points : (-6,9) and (-3,5)
f'(-5)=(9-5)/(-6-(-3))=-4/3
f'(-1) = ?
2 points : (-3,5) and (1,8)
f'(-1)=(5-8)/(-3-1)=3/4
The lines are perpendicular
The derivative at the points -5 and -1 are:
f’(-5) = -4/3
f’(-1) = 3/4
What is derivative at a point on line?The slope of the tangent line to the graph of a function at a point is called the derivative of the function at that point.
We consider the line on which where the x coordinate -5 lies.
It is the line with points (-3, 5) and (-6, 9).
Slope of the line = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex] = [tex]\frac{9-5}{-6+3} = \frac{-4}{3}[/tex]
f'(-5) = -4/3
We consider the line on which where the x coordinate -1 lies.
It is the line with points (-3, 5) and (1, 8).
Slope of the line = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex] = [tex]\frac{8-5}{1+3} = \frac{3}{4}[/tex]
f'(-1) = 3/4
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CAN SOMEONE PLEASE HELL ME WITH THIS PROBLEM? THANK YOU!!!
Answer:
71
Step-by-step explanation:
The reference angle is always the smallest angle with the x-axis.
The nearest x axis is at 0 or another name for 0 is 360
360 -289 = 71
The reference angle is 71
Find the APR, rounded to the nearest tenth of a percent (one decimal place) for the loan. Purchase a living room set for $4,900 at 8% add-on interest for 4 years. Enter only the number without % sign.
9514 1404 393
Answer:
14.3%
Step-by-step explanation:
We assume this question is asking for the annual interest rate for an amortized loan that would produce the same total repayment amount as if 8% simple interest were added to the $4900 loan amount. There is no formula for that, but there are a number of apps and spreadsheets that can calculate it. In the attached, we have use a graphing calculator.
The APR is about 14.3%.
_____
The amount to be repaid is calculated using the simple interest formula:
A = P(1 +rt) = $4900(1 +0.08·4) = $6468
Then the required monthly payment (for 48 months) is ...
$6468/48 = $134.75
__
The payment amount for a 48-payment loan at rate r on a principal of $4900 will be ...
A = 4900(r/12)/(1 -(1 +r/12)^-48)
In the attachment, we show the value of r (in percent) that would make the payment amount A be $134.75. We have done this by casting the problem in the form f(r) = 0 and looking for the x-intercept of f(r).
_____
Additional comment
The second attachment uses a spreadsheet for the same purpose. Here, we have used Go.ogle Sheets with a "Goal Seek" add-on to adjust the value in cell B5 so that the computed payment on the loan (cell B6) is the same as the value we calculated in cell B4.
We found the graphing calculator solution to be much quicker, though in that case we actually had to know the formula to use to calculate the payment. The payment formula is built into the spreadsheet.
[tex]3^n^+^1+9/3^n^-^1+1[/tex]
how do i solve it?
Answer:
Hello,
Step-by-step explanation:
[tex]\dfrac{3^{n+1}+9}{3^{n-1}+1} \\\\=\dfrac{9*(3^{n-1}+1)}{3^{n-1}+1}\\\\=9\\[/tex]
Given that f(x) = 2x + 9, find the value that makes f(x) = 27.
Answer:
9
Step-by-step explanation:
f(x) = 2x+9
f(x) = 27
so, you get:
2x+9=27
2x=18
x=9
Which ordered pair would form a proportional
relationship with the points in the graph?
O (44)
O (69)
O (9,6)
O (8,5)
What is the domain of the function graphed below?
Answer:
A. x<7
Step-by-step explanation:
The point at x=7 is an open circle, so the sign is <, not ≤
A store is advertising a new DVD player for $189.00. If the sales tax rate is 7.25 percent,
Answer:
then what's the question???..
Jose saves $22.45 a week which is 37% of his weekly pay. How much is Jose's weekly pay?
What are m and b in the linear equation, using the common meanings of m and b? 2 + 3x + 5 - 2x = y
y=mx+b is the general formula of linear equation
y=-2x+5+3x+2
y=1x+7
m=1
b=7
Linear equation given in the question is,
2 + 3x + 5 - 2x = y
To simplify this equation further,
Add like terms of the equation,(2 + 5) + (3x - 2x) = y
7 + x = y
Now compare this linear equation with the slope-intercept form of the linear equation,
y = mx + b
Here, m = slope of the line'
b = y-intercept
By comparing the equations,
m = 1
b = 7
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Please help!
It took Suki 127 minutes from start to finish to carve her pumpkin. Carving the pumpkin took her 13 fewer minutes than 10 times as long as it took her to pick the pumpkin out at the pumpkin patch. Write and solve an equation to find how long it took Suki to pick out her pumpkin.
9514 1404 393
Answer:
14 minutes
Step-by-step explanation:
Let t represent the time it took Suki to pick out her pumpkin. The given relation is ...
10t -13 = 127 . . . . . equation for minutes to carve
10t = 140 . . . . . . . . add 13
t = 14 . . . . . . . . . . divide by 10
It took Suki 14 minutes to pick out her pumpkin.
Fill in this blank spaces (1,3,5,7,9 , 11, 13, 15) _+_+_=30
Step-by-step explanation:
Just till the number 9 upside down to make it 6 then
6+11+13=30
The sum of three odd numbers can never be even. so I did it in that way.
I HOPE THIS WILL HELP U
STAY SAFE, STAY HAPPY
What is |1-8i|?
A.
B.
C
D
9514 1404 393
Answer:
(b) √65
Step-by-step explanation:
The modulus of a complex number is the root of the sum of the squares of the real and imaginary parts.
|1 -8i| = √(1² +(-8)²) = √(1+64) = √65
g Kristina Karganova invites 17 relatives to a party: her mother, aunts, uncles, brothers, 1 male cousin, and female cousins. If the chances of any one guest arriving first are equally likely, find the probabilities that the first guest to arrive is as follows. (a) A brother or an uncle (b) A brother or a cousin (c) A brother or her mother (a) The total number of outcomes is nothing and the number of outcomes in the event is nothing.
Answer:
7 / 17 ;
10 / 17 ;
5 / 17
Step-by-step explanation:
Guests :
Mother = 1
Aunts = 3
Uncles = 3
Brothers = 4
Male cousin = 1
Female cousin = 5
_________________
Total guests = 17
Since each of the guests have an equal probability of arrival :
Probability that first guest to arrive :
Brother or uncle :
Number of brothers =4
Number of uncles = 3
P(brother or uncle) = required outcome / Total possible outcomes
Required outcome (number of brothers + uncles) = (4 + 3) = 7
Total possible outcomes = total guests = 17
P(brother or uncle) = 7 / 17
2.)
P(brother or cousin) :
Required outcome = (number of brothers + cousins) = (4 + 1 + 5) = 10
Total possible outcomes = total guests = 17
P(brother or cousin) = 10/17
3.)
P(brother or mother) ;
Required outcome = (number of brothers + mother) = (4+1) = 5
Total possible outcomes = total guests = 17
P(brother or mother) = required outcome / Total possible outcomes = 5 / 17
