Question

A study of the effect of television commercials on 12-year-old children measured their attention span, in seconds. The commercials were for clothes, food, and toys.

Clothes	Food	Toys
34	38	64
30	34	50
44	51	39
35	42	48
28	47	63
31	42	53
17	34	48
31	43	58
20	57	47
	47	51
	44	51
	54

  Click here for the Excel Data File

1. Complete the ANOVA table. Use 0.05 significance level. (Round the SS and MS values to 1 decimal place and F value to 2 decimal places.)

Source df SS MS F p

Factors

Error

Total

2. Find the values of mean and standard deviation. (Round the mean and standard deviation values to 3 decimal places.)

Level	N	Mean	StDev
Clothes
Food
Toys

3. Is there a difference in the mean attention span of the children for the various commercials?

The hypothesis of identical means can definility be ............................... There is ....................... in the mean attention span.

4. Are there significant differences between pairs of means?

clothes have a mean attention span of a least ten minutes .......................... the other groups .

Answer 1

Anova: Single Factor
SUMMARY
Groups	Count, N	Sum	Mean	Variance	Std Dev.
Clothes	9	270	30	64	8
Food	12	533	44.417	52.629	7.255
Toys	11	572	52	53.4	7.308
ANOVA
Source of Variation	SS	df	MS	F	P-value
Between Groups	2436.1	2	1218.0	21.74	0.0000
Within Groups	1624.9	29	56.0
Total	4061.0	31

3.

The hypothesis of identical means can definitely be rejected. There is a difference in the mean attention span.