A psychology professor assigns letter grades on a test according to the following scheme. A: Top 9% of scores B: Scores below the top 9% and above the bottom 56% C: Scores below the top 44% and above the bottom 20% D: Scores below the top 80% and above the bottom 6% F: Bottom 6% of scores Scores on the test are normally distributed with a mean of 79.3 and a standard deviation of 8.4. Find the numerical limits for a D grade. Round your answers to the nearest whole number, if necessary.

Answers

Answer 1

Answer:

You get a D if you have a grade between 66 and 72.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Scores on the test are normally distributed with a mean of 79.3 and a standard deviation of 8.4.

This means that [tex]\mu = 79.3, \sigma = 8.4[/tex]

D: Scores below the top 80% and above the bottom 6%

So between the 6th and the 20th percentile.

6th percentile:

X when Z has a pvalue of 0.06. So X when Z = -1.555.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.555 = \frac{X - 79.3}{8.4}[/tex]

[tex]X - 79.3 = -1.555*8.4[/tex]

[tex]X = 66.2[/tex]

Rounds to 66

20th percentile:

X when Z has a pvalue of 0.2. So X when Z = -0.84.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-0.84 = \frac{X - 79.3}{8.4}[/tex]

[tex]X - 79.3 = -0.84*8.4[/tex]

[tex]X = 72.2[/tex]

Rounds to 72

You get a D if you have a grade between 66 and 72.


Related Questions

what is the value? when r equals 0

Answers

Answer:

I do not know the answer to this question

Step-by-step explanation:

What is the perimeter of the triangle?

Answers

Answer: 3y + 5 cm

Step-by-step explanation: The perimeter of a triangle

is just the distance around the outside of the figure.

So just add up all the sides.

So we have y + y + y + 5 and we get 3y + 5.

At a state university on the west coast, 13% of undergraduate students are of Asian origin. Among students of Asian origin, 11% major in Humanities, 7% in Social Sciences, 31% in Biological and Physical Sciences, 36% in engineering, and the remaining 15% in Business. Among students of other ethnicities, 19% major in Humanities, 16% in Social Sciences, 12% in Biological and Physical Sciences, 18% in engineering, and the remaining 35% in Business. One undergraduate student majoring in Business is randomly selected from this university. Find the probability that the student is not of Asian origin.

Answers

Answer:

0.9398 = 93.98% probability that the student is not of Asian origin.

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Business student

Event B: Not of Asian origin.

Probability that the student is an undergraduate majoring in business.

15% of 13%(Of Asian origin).

35% of 100 - 13 = 87%(Not of Asian origin). So

[tex]P(A) = 0.15*0.13 + 0.35*0.87 = 0.324[/tex]

Business student and not of Asian origin:

35% of 87%. So

[tex]P(A \cap B) = 0.35*0.87 = 0.3045[/tex]

One undergraduate student majoring in Business is randomly selected from this university. Find the probability that the student is not of Asian origin.

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.3045}{0.324} = 0.9398[/tex]

0.9398 = 93.98% probability that the student is not of Asian origin.

4 to the power of3 -(2+2to the power of 3) x 5​

Answers

Answer:

14

Step-by-step explanation:

Given the following equation;

4³ - (2 + 2³) * 5

4*4*4 - (2 + 2*2*2) * 5

64 - (2 + 8) * 5

64 - (10) * 5

64 - 50 = 14

Note: the rule of BODMAS was applied.

Sam plans to use two flags on his float for the parade. Each flag is a right triangle and the triangles are similar.What is the width, x, of the larger flag in feet? halp please!!! 100 POINTS

Answers

Answer:

6.25 ft

Step-by-step explanation:

The smaller flag width is 5. And the larger flag is not that big in size. So the close answer is 6.25

Answer:

6.25ft

Step-by-step explanation:

Factorise
1) 9a^2 - 6a​

Answers

Answer:

9a^2 - 6a

taking common

3a(3a-2)

How do you find the slope to (3,12),(3,-17)

Answers

Answer:

you plot them together

1. draw a t shape and then plot it like x then y

Answer:

trust your instincts

Step-by-step explanation:

decide on your own destiny i can not interfeir

1/2 of 2/2 = ???????????

Answers

Answer:

0.5

Step-by-step explanation:

Lula has two dogs, one 35 pounds, the other 25 pounds. What is the average weight of Lula's dogs?

Answers

Answer:

30

Step-by-step explanation:

25+35= 60

60/2=30

Answer: 30

Step-by-step explanation:

The term average has a number of different meanings. Most generally, it is a single number that is used to represent a collection of numbers. In the context of mathematics, "average" refers to the mean, specifically, the arithmetic mean. It is a relatively simple statistical concept that is widely used in many areas.

The equation below is one of the more commonly understood definitions of the average: [tex]Average =[/tex] [tex]\frac{Sum}{Count}[/tex]

Help ASAP ASAP

Help asappp

Answers

Answer:

-3.9

Step-by-step explanation:

y/0.3 - 1.4= -14.4
•0.3. •0.3
y-1.4= -4.32
+1.4= +1.4
y= -2.92

20 points to answer !!
In your own words, describe a situation in your own life that involves quadrilaterals..... (see picture above)

Answers

The math teacher made me write a page about a rectangle

the burger king sign is a rectangle i had burger king last week

What is the slope-intercept equation for the line below?
5
(4,3)
(0, 1)
5
O A. y=2x+1
B. y=-3x+1
O C. y=-2x+1
O D. y = 2x+1

Answers

Answer:

is there a pic you could provide?

Step-by-step explanation:

The slope-intercept equation for the line is,

⇒ y = 1/2x + 1

What is Equation of line?

The equation of line in point-slope form passing through the points

(x₁ , y₁) and (x₂, y₂) with slope m is defined as;

⇒ y - y₁ = m (x - x₁)

Where, m = (y₂ - y₁) / (x₂ - x₁)

Given that;

Two points on the line are (4, 3) and (0, 1).

Now,

Since, The equation of line passes through the points (4, 3) and (0, 1).

So, We need to find the slope of the line.

Hence, Slope of the line is,

m = (y₂ - y₁) / (x₂ - x₁)

m = (1 - 3) / (0 - 4)

m = - 2 / - 4

m = 1/2

Thus, The equation of line with slope 1/2 is,

⇒ y - 3 = 1/2 (x - 4)

⇒ y - 3 = 1/2x -2

⇒ y = 1/2x + 1

Therefore, The slope-intercept equation for the line is,

⇒ y = 1/2x + 1

Learn more about the equation of line visit:

https://brainly.com/question/18831322

#SPJ7

pls answer I'll mark u brainliest urgent ​

Answers

Answer:

a = 110

Please mark as brainliest if answer right

Have a great day, be safe and healthy  

Thank u  

XD

Answer:

A=110

that is what I think

Help plsssss!!!!!!!!!!!!!

Answers

Answer:

Percent, Part, whole, I am not sure the rest hope this helped though

Step-by-step explanation:

Answer:

15% is the percent, 9$ is the part and the original price is the whole

the original price is 60$ and the coustomer buys it for 51$

9. The radius of sphere is increasing at a rate of 3cm/minute. Find the rate of change of volume
when r=2cm *

V = 12
48л
16л
64 л
32T

Answers

Answer:

48π

Step-by-step explanation:

Given that,

The radius of the sphere is increasing at a rate of 3cm/minute, [tex]\dfrac{dr}{dt}=3\ cm/minute[/tex]

The volume of a sphere is given by :

[tex]V=\dfrac{4}{3}\pi r^3[/tex]

Differentiating both sides wrt t.

[tex]\dfrac{dV}{dt}=\dfrac{4}{3}\pi \times 3r^2\times \dfrac{dr}{dt}\\\\=4\pi r^2\times \dfrac{dr}{dt}[/tex]

Put r = 2 cm and dr/dt = 3 cm/minute

So,

[tex]\dfrac{dV}{dt}=4\pi r^2\times \dfrac{dr}{dt}\\\\\dfrac{dV}{dt}=4\pi \times 2^2\times 3\\\\\dfrac{dV}{dt}=48\pi[/tex]

Hence, the correct option is (a) "48π".

The mean length of 9 childrens' big finger is 6.8cm.
The mean length of 3 adults' big finger is 11cm.
What is the mean length (rounded to 2 DP) of these 12 people's big finger?

Answers

Answer:

The mean length of these 12 people's big finger is of 7.85 cm.

Step-by-step explanation:

Mean value:

Sum of the values of all observations divided by the number of observations.

In this question:

9 + 3 = 12 total observations

Sum:

[tex]9*6.8 + 3*11 = 94.2[/tex]

So

[tex]M = \frac{94.2}{12} = 7.85[/tex]

The mean length of these 12 people's big finger is of 7.85 cm.

Type in a value that represents as likely as not in a decimal form.

Answers

Answer:

I Need Numbers Somthing....... Its Imposable to answer this

Step-by-step explanation:

Find the RANGE for the function f(x) = -4x - 9 if D = {1/2 ,0}

Answers

Answer:

-11, and -9 is the range for 1/2 and 0 respectively

Step-by-step explanation:

the sum of the ages of tracy and her mother is 60 if tracys present age is y years write a linear expression for her mothers age after 5 years​

Answers

Answer:

Step-by-step explanation:

m = 60-y

m+5 = 65-y

The area of the triangle below is 23.4 square inches. What is the length of the base?
6 in is the height

Answers

Answer:

543

Step-by-step explanation:

i am smart

WRITE AN EQUETION TO REPREDENT ECH ONE ​

Answers

Answer:

2x=3

W+1.3=2.7

3y=5.1

z+1/3=1/2

Step-by-step explanation:

You just add up all on the left to equate that on the right

2x=3

W+1.3=2.7

3y=5.1

z+1/3=1/2

In case you have to solve:

x=3/2

W=2.4

y=1.7

z=1/6



2(4y) + 4(3r) answer

Answers

Answer: 8y+12r

Step-by-step explanation:

Take the equation

2(4y)+4(3r)

Distribute the 2 and 4 into the parenthesis'

8y+12r

Let's simply:
___________
2(4y) + 4(3r)
= 8y + 12r

the answer to your question is 12r + 8y

Pls help me with this problem. Also the answer has to be in terms of pi

Answers

Answer: 25pi
Explanation: area = piR^2 so 10(radius)^2 = 100pi, only 1/4 of the circle is there so divide the area found (100pi) by 4 to find the one quarter of the circle.

A student has started a lawn care business. He charges $15 per hour to mow lawns and $20 per hour for gardening. Because he is still in school, he is only allowed to work for at most 20 hours per week. His goal is to make at least $300 per week.
Create a system of equations or inequalities that models the situation.
Define the variables you use.

Answers

Answer:

10/20

Step-by-step explanation:

$15 for 10 hours and $20 for 10 hours

Need help ASAP !!!
Solve for u

Answers

Answer:

3.46 or ..

[tex] 2\sqrt{3} [/tex]

Step-by-step explanation:

because you use sin(60) = 3/u

PLEASE HELP DUE TONIGHT

Answers

Answer:

The answer should be 20,000 feet

Step-by-step explanation:

sin 0 =opposite/hypotenuse

sin 30 = AB/AC

sin 30 = 10000/c

c= 10000/sin 30

c=10000/1/2

c=20,000 feet

i will give you brainliest whoever answers correct first!!

Answers

Answer:

74.4 (llllllllllll ignore this i need 20 characters to answer)

You NEVER distribute a coefficient of an absolute value. True or False?

Answers

Answer:

TRUE!!!!!!!!!

Step-by-step explanation:

First one to answer gets BRAINLIEST no cap look at the picture.

Answers

Answer: 150

(6+9)20 = 300
300/2 = 150

PLS HELP
WILL GIVE BRAINIEST

The points plotted below are on the graph of a polynomial. Which of the
following x-values is the best approximation of a root of the polynomial?
Check all that apply.

A. X-1.1
B. X= 4.3
C. x=2.4
D. X=6
E.X=1

Answers

Answer:

I don't know the answer but have a site that helps me with math, its called

Step-by-step explanation:

Just check it out

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