Question

An educator wants to evaluate four different methods aimed at reducing the time children spend "off task" in the classroom. To test these methods, she implements one method in each of four similar classrooms and records the time spent off task (in minutes) in each classroom. The results are given in the table.

Classroom Method
A	B	C	D
1	1	0	3
1	5	0	2
4	3	4	4
4	4	3	5
0	2	3	4
5	2	5	4
2	4	5	2
4	0	6	2
3	1	5	4

(a) Complete the F-table. (Round your answers to two decimal places.)

Source of Variation	SS	df	MS	F
Between groups
Within groups (error)
Total

(b) Is it necessary to compute a post hoc test? Explain. (Assume alpha equal to 0.05.)

Yes, post hoc analyses are appropriate because the ANOVA is significant.No, post hoc analyses are not appropriate because the ANOVA is not significant.    

Answer 1

Sol:

Install analysis tool pak in excel.

Go to Data>Data analysis>ANOVA single factor

You will get

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
A	9	24	2.66666667	3
B	9	22	2.44444444	2.777778
C	9	31	3.44444444	4.777778
D	9	30	3.33333333	1.25
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	6.527777778	3	2.17592593	0.737255	0.537588	2.90112
Within Groups	94.44444444	32	2.95138889
Total	100.9722222	35

ANSWER;

ANOVA
Source of Variation	SS	df	MS	F
Between Groups	6.53	3.00	2.18	0.74
Within Groups	94.44	32.00	2.95
Total	100.97	35.00

(rounded to 2 decimals as specified

Solutionb:

here p=0.53758

p>0.05

Fail tot reject Ho.

Meaning

All 4 group means are equal.

No need to conduct post hoc test.

No, post hoc analyses are not appropriate because the ANOVA is not significant.