Question

Suppose a university advertises that its average class size is 30 or less. A student organization is concerned that budget cuts have led to increased class sizes and would like to test this claim. A random sample of 43 classes was​ selected, and the average class size was found to be 32.4 students. Assume that the standard deviation for class size at the college is 7 students. Using alpha equals 0.01​, complete parts a and b below. a. Does the student organization have enough evidence to refute the​ college's claim? Determine the null and alternative hypotheses. Upper H 0​: mu ▼ less than or equals equals not equals less than greater than greater than or equals nothing Upper H 1​: mu ▼ greater than or equals not equals greater than less than less than or equals equals nothing

Answer 1

Solution:

Given that,

= 30

= 32.4

s = 7

n = 43

The test statisc t is,

t = ( -  ) /  (s /n)

t =( 32.4 - 30) / (7 / 43)

t = (2.4 *  43) / 7

t = 2.25

Test staistic = 2.25

Degrees of freedom = df = n - 1 = 43 - 1 = 42

Using t distribution table

P value = 0.0149

P value >  

0.0149 > 0.01

Do not reject  the null hypothesis