# Descriptive Statistics, Student and Enrollment Distribution

Question 1 and 2 involve the random variable x with probability distribution given below.

x -2 4 5 6 7

P(x) 0.15 0.05 0.3 0.1 0.4

determine the expected value of x.

determine the standard deviation of x.

#2

Below is a compilation of student distribution in our four statistics classes from the summer of 2009.

course stat 200 stat 225 stat 230 stat 250

percentage 45.8 12.0 32.8 9.4

#3

The enrollment report for the summer of 2011 is given as follows

course stat 200 stat 225 stat 230 stat 250

frequency 249 71 133 47

At the 1% significant level, do the data provide sufficient evidence to conclude that 2011's enrollment distribution differs from the 2009 distribution?

Show all work: include the hypotheses, the computation of the test statistic, state the critical value, and state the conclusion of the test.

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#### Solution Summary

The following posting helps calculation expected value, standard deviation, and helps determine student distribution and enrollment distribution. Calculations are given in Excel.