Question

Use the following problem to answer questions on this quiz:

A large school district has several middle schools. Three schools were randomly chosen, and four classes were selected from each. The numbers of pupils in each class are shown here. At α = 0.05, is there sufficient evidence that the mean number of students per class differs among schools?

MS 1MS 2MS 3

212828

252223

192526

173022

162326

   

x¯1=19.6x¯2=25.6x¯3=25.0

s12=12.8s22=11.3s32=6.0

Find the grand mean, X¯GM:
(Round to four decimal places.)

Find the between-group variance, sB2:
(Round to four decimal places.)

Find the within-group variance, sW2:
(Round to four decimal places.)

Using Table H (Links to an external site.), find the critical value(s) and type in the answer boxes:

Negative Critical Value:  −
(Type "none" if there is not a negative critical value.)

Positive Critical Value:  +
(Type "none" if there is not a positive critical value.)

Answer 1