Answer:
B. Z= -2.55
Step-by-step explanation:
To solve this question, first we need to understand the central limit theroem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction of normal variables:
When two normal variables are subtracted, the mean is the subtraction of the means while the standard deviation is the square root of the sum of the variances.
11 of 50 men believe that sexual discrimination is a problem:
This means that:
[tex]p_M = \frac{11}{50} = 0.22, s_M = \sqrt{\frac{0.22*0.78}{50}} = 0.0586[/tex]
19 of 40 women believe that sexual discrimination is a problem:
This means what:
[tex]p_W = \frac{19}{40} = 0.475, s_W = \sqrt{\frac{0.475*0.525}{40}} = 0.079[/tex]
Difference between the proportion of men and women:
[tex]p_D = p_M - p_W = 0.22 - 0.475 = -0.255[/tex]
[tex]s_D = \sqrt{s_M^2+s_W^2} = \sqrt{0.0586^2+0.079^2} = 0.0984[/tex]
A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination.
This means that the null hypothesis is that they do not differ, than is, the difference is 0. So
[tex]H_0: p_D = 0[/tex]
At the alternate hypothesis, we test that they differ, that is, the difference is different of 0. So
[tex]H_a: p_D \neq 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis and s is the standard error.
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
For the sample, we calculated that:
[tex]X = -0.255, s = 0.0984[/tex]
The value of the test-statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{-0.255 - 0}{0.0984}[/tex]
[tex]z = -2.59[/tex]
Closes answer is Z = -2.55, option B.
In a popular online role playing game, players can create detailed designs for their
character's "costumes," or appearance. Justin sets up a website where players can buy
and sell these costumes online. Information about the number of people who visited
the website and the number of costumes purchased in a single day is listed below.
237 visitors purchased no costume.
17 visitors purchased exactly one costume.
24 visitors purchased more than one costume.
Based on these results, express the probability that the next person will purchase no
more than one costume as a fraction in simplest form.
Answer:
uhm I don't know this one.
Step-by-step explanation:
Triangle PQR has vertices P(−3,4), Q(−8,3), and R(−1,−6). Triangle PQR is dilated by a scale factor of 8 centered at the origin to get triangle P′Q′R′.
What are the coordinates of points P′, Q′, and R′ of the image?
P′(−38,−12), Q′(−1,38), R′(−18,−34)
P′(−3,32), Q′(−8,24), R′(−1,−48)
P′(−24,4), Q′(−64,3), R′(−8,−6)
P′(−24,32), Q′(−64,24), R′(−8,−48)
Answer:
The coordinates of points P', Q' and R' are (-24, 32), (-64, 24) and (-8,-48), respectively.
Step-by-step explanation:
Vectorially speaking, the dilation of a vector with respect to a given point is defined by the following formula:
[tex]P'(x,y) = O(x,y) + r\cdot [P(x,y)-O(x,y)][/tex], [tex]r > 1[/tex] (1)
Where:
[tex]O(x,y)[/tex] - Point of reference.
[tex]P(x,y)[/tex] - Original point.
[tex]P'(x,y)[/tex] - Dilated point.
[tex]r[/tex] - Scale factor.
If we know that [tex]O(x,y) = (0,0)[/tex], [tex]P(x,y) = (-3, 4)[/tex], [tex]Q(x,y) = (-8,3)[/tex], [tex]R(x,y) = (-1,-6)[/tex] and [tex]r = 8[/tex], then the new coordinates of the triangle are, respectively:
[tex]P'(x,y) = (0,0) + 8\cdot [(-3,4)-(0,0)][/tex]
[tex]P'(x,y) = (-24, 32)[/tex]
[tex]Q'(x,y) = (0,0) + 8\cdot [(-8,3)-(0,0)][/tex]
[tex]Q'(x,y) = (-64, 24)[/tex]
[tex]R'(x,y) = (0,0) + 8\cdot [(-1,-6)-(0,0)][/tex]
[tex]R'(x,y) = (-8,-48)[/tex]
The coordinates of points P', Q' and R' are (-24, 32), (-64, 24) and (-8,-48), respectively.
Answer:
(-24, 32), (-64, 24) and (-8,-48)
Step-by-step explanation:
6
A natural gas company charges a $23.13 connection fee plus $1.34 per 10 cubic feet of gas used. In the winter peak usage
months, November through February, they charge each customer a peak usage surcharge of $23.22. If a family uses 100 cubic feet
of gas, how much will their bill have increased because of the peak usage surcharge?
A. $232.20
B. $59.75
C. $46.35
OD. $23.22
Answer:
A is what i got but i could of done the math wrong sorry
A company charges a shipping fee that is 6.5% of the purchase price for all items it ships. What is the fee to ship an item that costs $60? Round to the nearest cent (hundredths place). *
Answer:
The answer is $2.52.
Step-by-step explanation:
56 x .045= $2.52
The rectangle below is show with dimensions in inches
Answer:21/64
Step-by-step explanation:
Do 3*7 to get 21
And 8*8 to get 64.
To multiply fractions you multiply the denominators together and then the numerators together
find the next number 2,5,12,25,54
Answer:
Step-by-step explanation:
The next number is 110
Please explain how you got this
Answer:
area = 68 ft²
Step-by-step explanation:
area = 1/2(b1 + b2)(h) = 1/2(9 + 8)(8) = 68 ft²
Answer:
68
Step-by-step explanation:
First find the internal square area (64) then calculate the outer triangles (2 each) to get 68 plz thx, 5 str and mark brainliest
answer all of them please
easy math questions for 20 points
h=-4.9(+-13)(t+2)
h=-4.9(+-13)(t+2)
Answer:
h=63.7t+127.4
Step-by-step explanation:
PLEASE HELP ME PLZ IN I GET IT RIGHT I WILL GIVE U A BRAINLY AND PLZ NO LINK THAT DON’T HELP AT ALL
if the area of square A is 225 ft2 and the area of square B is 400 ft2 what is the area of square c?
Part C
How many cubic blocks are needed to fill the fish tank?
Answer:
[tex]2\frac{2}{3}[/tex] cubic blocks
Step-by-step explanation:
The given parameters are:
[tex]Length = \frac{1}{2}yd[/tex]
[tex]Width = 16yd[/tex]
[tex]Height =\frac{1}{3}yd[/tex]
Required
Number of cubic blocks to fill the tank
To do this, we simply calculate the volume of the tank by:
[tex]Volume = Length * Width * Height[/tex]
This gives:
[tex]Volume = \frac{1}{2} * 16 * \frac{1}{3}[/tex]
[tex]Volume = \frac{16}{6}[/tex]
Simplify
[tex]Volume = \frac{8}{3}[/tex]
Express as mixed numbers
[tex]Volume = 2\frac{2}{3}yd^3[/tex]
A triangle has base angles of 52.5 degrees each. What is the measurement of the third angle?
Answer:
The answer is 75 degrees
Step-by-step explanation:
All triangles interior angles will at up to 180. 52.5+52.5= 105. 180-105= 75 degrees.
What is the answer to number 12?
Answer:
12) 2.5
the height then is 2.5.
Step-by-step explanation:
42.9/3.3 = 13
32.5/13 = 2.5
Have a nice day!
simplify. (write without the absolute value sign): |x+3|, if x=2
Answer:
5
Step-by-step explanation:
|x+3| when x = 2 is |2+3| = |5| = 5
Answer:
5
Step-by-step explanation:
Substitute 2 in for x
|2+3| = 5
This would take the absolute value of the answer, or in other words once you solve the equation it will remove any negatives to return a positive number.
For a Saturday matinee, adult tickets cost $7.50 and kids under 12 pay only $6.00. If 80 tickets are sold for a total of $525, how many of the tickets were adult tickets and how many were sold to kids under 12?
They sold ___ adult tickets and _____ kids tickets.
Answer:
They sold 30 adult tickets and 50 kids tickets.
Step-by-step explanation:
This question is solved by a system of equations.
I am going to say that:
x is the number of adult tickets sold
y is the number of kids tickets sold.
80 tickets are sold
This means that [tex]x + y = 80[/tex], or also, [tex]x = 80 - y[/tex]
For a Saturday matinee, adult tickets cost $7.50 and kids under 12 pay only $6.00. Tickets were sold for a total of $525.
This means that:
[tex]7.5x + 6y = 525[/tex]
Since [tex]x = 80 - y[/tex]
[tex]7.5(80 - y) + 6y = 525[/tex]
[tex]600 - 7.5y + 6y = 525[/tex]
[tex]1.5y = 75[/tex]
[tex]y = \frac{75}{1.5} = 50[/tex]
[tex]x = 80 - y = 80 - 50 = 30[/tex]
They sold 30 adult tickets and 50 kids tickets.
The area of a rectangular note card is 35 square inches. The perimeter is 24 inches. What are the
dimensions of the note card?
inches by
inches
Answer:
5in by 7in
Step-by-step explanation:
2*(l+w)= 24 => l+w= 12
Le= 35
It is easy to see that 35=5*7 and 12= 5+7
So 5 and 7 are the dimensions of the card
Will give brainliest
Answer:
31.6%
6.67%
14.3%
Step-by-step explanation:
Find the Total surface area of the triangular prism below.
Answer:
The surface area of any prism is the total area of all its sides and faces. A triangular prism has three rectangular sides and two triangular faces. To find the area of the rectangular sides, use the formula A = lw, where A = area, l = length, and h = height. To find the area of the triangular faces, use the formula A = 1/2bh, where A = area, b = base, and h = height. Once you have the areas of all sides and faces, you simply add them together to get the surface area.
Step-by-step explanation:
Formula
Area of a triangle
A = 1/2bh
Area of a rectangle
A = lw
Surface area of triangular prism
SA = bh + (s1 + s2 + s3)H
Hope it helps... Please mark as the Brainliest!!!
We are going to sell shirts during spirit Week. The shirts come in 3 colors: black, white, and gold. Students may also choose from 2 different colors of ink and 2 different designs. How many different types of shirts can be made?
Answer:
I don’t really know but ill go with 21
Step-by-step explanation:
For some reason
7 and - 1 1/2 on the number line?
solve 3y+1/2x-w=0 for y
9514 1404 393
Answer:
y = 1/3w -1/6x
Step-by-step explanation:
Subtract the terms not containing y, then divide by the coefficient of y.
[tex]3y+\dfrac{1}{2}x-w=0\\\\3y=w-\dfrac{1}{2}x\qquad\text{subtract non-$y$ terms}\\\\\boxed{y=\dfrac{1}{3}w-\dfrac{1}{6}x}\qquad\text{multiply by $\dfrac{1}{3}$}[/tex]
need help.
The scatter plot and line of best fit below show the length of 9 people's femur (the long leg bone in the thigh) and their height in centimeters. What is the meaning of the xx-value on the line when y=160y=160?
Answer:
c
Step-by-step explanation:
The true statement is (d) The expected height of 160 cm when the femur length has a length of 42.5 cm
How to interpret the scatter plot?From the given figure, we have:
x values represents the femur length in centimetersy values represents the height in centimetersSo, when the y value is 160, the x value is:
The expected height of 160 cm when the femur length has a length of 42.5 cm
Hence, the true statement is (d)
Read more about scatter plots at:
https://brainly.com/question/6592115
What is the area of the following figure?
Answer:
The answer is 59in
Answer:
242 in^2
Step-by-step explanation:
Area of a rectangle is length x width.
Area of rectangle: 24 in x 7 in = 168 in^2
Area of a trapezoid is 1/2(height)(base 1 + base 2)
Area of the trapezoid on top is 1/2(4)(13+24) = 2(13 + 24) = 2(37) = 74.
The total are is 168 + 74 = 242 in^2
Sasha modeled an expression as shown below.
125
34
х
Which answer choice could NOT represent this expression?
A x + 34 = 125
B
125 - 34 = x
С
125 - X = 34
D
125 + 34 = X
it should either a or b
please help me. please please please
Answer:
[tex]\frac{27}{8}[/tex]
Step-by-step explanation:
[tex]\left(\frac{16}{81}\right)^{\frac{-3}{4}}=\frac{16^{\frac{-3}{4}}}{81^{\frac{-3}{4}}}[/tex]
[tex]=\frac{2^{-3} }{3^{-3} }[/tex]
[tex]=\frac{\frac{1}{8}}{\frac{1}{27}}[/tex]
[tex]=\frac{1*27}{8*1}[/tex]
[tex]=\frac{27}{8}[/tex]
You were born, your mother deposited 2000 in an account that pays 5% simple interest. How much would the balance be in your account when you enter college 18 years after?
A. 18000
B. 1800
C. 3800
D. 20000
Answer:
C
Step-by-step explanation:
the formula for simple interest is given as A=P(1+rt), where A is the final balance, P is the initial principal balance (the amount of money that you start out with), r is the annual interest rate, and t is the time
we know that the mom deposited 2000 into an account when the person was born. This is our initial principal balance (the amount of money started out with)
substitute that value into the formula to get:
A=2000(1+rt)
we also know the rate, which is 5% and the time, which is 18
5%=0.05 (we need it as a decimal)
so substituting the values into the equation:
A=2000(1+0.05*18)
A=2000(1+0.9)
A=2000(1.9)
A=3,800
therefore the answer is C
Hope this helps!
please help I'll give brainliest
Find the surface area of a number cube if the height is 3cm.
Answer: 54 cm²
Step-by-step explanation:
To find the area we have to:
1) Multiply 3 x 3= 9 (we do this because a cube has equal sides so if the height is 3 then the base will be 3).
2) Then take 9 and multiply it by the number of sides of a cube (6 sides)
so, do 9 x 6 = 54cm²
Hope that helped! :)
Answer:
54 cm^3
Step-by-step explanation:
here's your solution
==> surface area of cube = 6a^2
==> a = 3 cm
==> surface area = 6*3^2
==> surface area = 6*9
==> surface area of cube = 54 cm^3
hope it helps
Julie printed out a picture of each of the five members of her favorite band to decorate her bedroom door. Each picture measures 8
inches by 10 inches. Once decorated, how many square inches of Julie's door will be covered by these pictures?
OA.
400 square inches
OB. 320 square inches
OC. 480 square inches
OD
180 square inches
Mary Jo spends $2,300 to buy stock in two companies. She pays $19 a share to one of the companies and $24 a share to the other. If she ends up with a total of 100 shares, how many shares did she buy at $19 a share and how many did she buy at $24 a share?
She bought ____ shares at $19 and ___ shares at $24.
Answer:
She bought _20___ shares at $19 and _80__ shares at $24.
Step-by-step explanation:
x + y = 100
19x + 24y = 2300
-19x - 19y = -1900
5y = 400
y = 80
x + 80 = 100
x = 20
She bought _20___ shares at $19 and _80__ shares at $24.