Lab031011A

# Lab031011A - Suppose the GPAs of students in entire IU...

This preview shows pages 1–2. Sign up to view the full content.

Suppose the GPAs of students in entire IU system follows Normal distribution with a mean 3.10  1. What is the probability that a randomly selected IU student's GPA is equal to 3.10? 0 It is a continuous random variable, so that the probability of the variable's being a particular value is zero 2. What is the probability that a randomly selected IU student's GPA is between 2.7 and 3.5? =NORMDIST(3.5,3.1,0.35,1) - NORMDIST(2.7,3.1,0.35,1) =  0.75 3. Suppose an honor society recruites students that have GPAs within top 1% of all IU students. Then, w =NORMINV(0.99,3.1,0.35) =  3.91  A researcher randomly selects 100 IU students, surveys their GPAs and calculates a sample mea 4. What is the center and dispersion of the distribution of mean GPAs from samples of 100? How about E(X_bar) = E(X) =  3.10  sigma(X_bar) = sigma(X)/sqrt(n) = 0.35/sqrt(100) =  0.04 Since the population follows normal distribution, the sample mean exactly follows normal distribution. 5. What are the answers to the previous question if the population GPA distribution is not normal? The center and dispersion remain the same. Even if the population distribution is NOT normal, by the Central Limit Theorem (n>30), the sample mea

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 07/01/2011 for the course ECO 370 taught by Professor Camp during the Spring '11 term at Indiana State University .

### Page1 / 118

Lab031011A - Suppose the GPAs of students in entire IU...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online