Question

A community college Math instructor feels that the average number of units students enroll in each semester has increased since he was a student at community college. Looking up data from the year the instructor started teaching, the mean number of units community college students enrolled was 14.3 units, with a population standard deviation of 3.2 units. The Math instructor took a sample of 40 of the current community college students and found that the sample had a mean number of units enrolled of 15.7 units. Assume the population of ages of community college students is normally distributed and that the population standard deviation has remained the same.

Test at the 5% significance level if the mean number of units enrolled for community college students is now greater than 14.3 units.

In the statements below, select the correct value/response to fill in the blanks:

(i) Hypotheses
H0 :  μ =

(ii) Test Statistic

(iv) Decision

Answer 1

Given,

i) Hypothesis is,

ii) test statistic,

The corresponding p value is,

p = 0.0028

iv)

Since the p value is less than level of significance, we reject the null hypothesis. We conclude that the average number of units students enroll in each semester has increased since he was a student at community college.