Question

To test whether or not there is a difference between treatments A, B, and C, a sample of 12 observations has been randomly assigned to the 3 treatments. You are given the results below.

Treatment	Observation
A	20	30	25	33
B	22	26	20	28
C	40	30	28	22

           The test statistic to test the null hypothesis equals:

Answer 1

excel data analysis tool for one factor anova,steps are: write data>menu>data>data analysis>anova :one factor>enter required labels>ok, and following o/p Is obtained,

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
A	4	108	27	32.66667
B	4	96	24	13.33333
C	4	120	30.00	56.00
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	72.00	2	36.0000	1.0588	0.386	4.26
Within Groups	306.00	9	34.000
Total	378.00	11

Ho: µ_A=µ_B=µ_C
H1: not all means are equal

F stat = 1.0588

so,

           The test statistic to test the null hypothesis equals: = 1.0588