In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 73 and a standard deviation of 9. Grades are assigned such that the top 10% receive A's, the next 20% received B's, the middle 40% receive C's, the next 20% receive D's , and the bottom 10% receive F's. Find the lowest score on the final exam that would qualify a student for an A, a B, a C, and a D. Click here to view Page 1 of the Standard Normal Table Click here to view Page 2 of the Standard Normal Table. The lowest score that would qualify a student for an A is (Round up to the nearest integer as needed.)

Question

I don't understand how to solve for this. I'm having trouble understanding the percentages

 

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 73 and a standard deviation of 9. Grades are assigned such
that the top 10% receive A's, the next 20% received B's, the middle 40% receive C's, the next 20% receive D's , and the bottom 10% receive F's. Find the lowest score
on the final exam that would qualify a student for an A, a B, a C, and a D.
Click here to view Page 1 of the Standard Normal Table
Click here to view Page 2 of the Standard Normal Table.
The lowest score that would qualify a student for an A is
(Round up to the nearest integer as needed.)

Image Transcription

In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 73 and a standard deviation of 9. Grades are assigned such that the top 10% receive A's, the next 20% received B's, the middle 40% receive C's, the next 20% receive D's , and the bottom 10% receive F's. Find the lowest score on the final exam that would qualify a student for an A, a B, a C, and a D. Click here to view Page 1 of the Standard Normal Table Click here to view Page 2 of the Standard Normal Table. The lowest score that would qualify a student for an A is (Round up to the nearest integer as needed.)

Expert Answer

Want to see the step-by-step answer?

See Answer

Check out a sample Q&A here.

Want to see this answer and more?

Experts are waiting 24/7 to provide step-by-step solutions in as fast as 30 minutes!*

See Answer
*Response times vary by subject and question complexity. Median response time is 34 minutes and may be longer for new subjects.
Tagged in

Related Statistics Q&A

Find answers to questions asked by student like you

Q: Determine whether to use a permutation or combination to answer each question, and then determine th...

A: Permutation rule:There are n different items and r number of selections and the selections are made ...

Q: A random sample of 26 local sociology graduates scored an average of 458 on the GRE advancedsociolog...

A: From the provided information, there are 26 sample (N) with the average (x̄) score of 458 and standa...

Q: A sample is selected from a population with μ = 52, and a treatment is administered to the sample. I...

A:  The greatest likelihood of reject the null hypothesis is occurred when z-score (calculated value) i...

Q: Pulse rate of women are normally distributed with a mean of 77.5 beats per minute and a standard dev...

A: Standard normal distribution:• The normal distribution has mean as 0 and standard deviation as 1.• T...

Q: Help

A: Uniform distribution:A random variable, say X ~ U(0,1) is said to be standard uniform distribution t...

Q: You are planning a three-day trip to Seattle, Washington, in October. Use the fact that on each day,...

A: The pmf of the binomial random variable with parameters n = 3 and p = 0.5 is given as follows:

Q: A study is being conducted of the faculty salaries for a public university. Of the 1200 tenuretrack ...

A: a.In this context, the faculties are named as 3 stratum. That is full professors, associate professo...

Q: The scores on the Wechsler Adult Intelligence Scale are approximately Normal, with ?=100μ=100 and ?=...

A: Note:Hey there! Thank you for the question. From you question, it logically seems that the given sco...

Q: Find ? such that the proportion of observations that are less than ? in a standard normal distributi...

A: z-left tailed value:The area left to the particular point in the standard normal distribution is 0.2...