Question

Suppose a university advertises that its average class size is 36 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 40 classes was​ selected, and the average class size was found to be 38.7 students. Assume that the standard deviation for class size at the college is 8 students. Using alpha equals 0.05​, complete parts a and b below.

A. determine the p-value for this test using excel steps

Answer 1

Null hypothesis      

      
Alternative hypothesis   

   
      

We have given,      
Population mean for given example =36
Sample mean=38.7
Population standard deviation =   8
Sample size for given example =   40
Level of significance =   0.05
Z test statistic formula


=2.14  

P value = 0.0162........................by using Excel command =1-NORMSDIST(2.14)