Question

BigShots, Inc. is a specialty e-tailer that operates 87 catalog Web sites on the Internet. Kevin Conn, Sales Director, feels that the style (color scheme, graphics, fonts, etc.) of a Web site may affect its sales. He chooses three levels of design style (neon, old world, and sophisticated) and randomly assigns six catalog Web sites to each design style. Analysis of Kevin's data yielded the following ANOVA table.

Source of Variation	SS	df	MS	F
Between Groups	68102.33	2	34051.17
Within Groups	29177.67	15	1945.178
Total	97280	17

Using α = 0.05, the critical F value is __________.

		19.45
		3.68
		3.57
		19.43

Answer 1

F = MS_Between Group / MS_Within Group

F = 34051.17 / 1945.178 = 17.5054

F = 17.5054

Critical value:

F_{,DF_Between group,DF_Within group} = F_0.05,2,15 = 3.68 ..................From F table

ANSWER: B. 3.68

Answer 2

To find the critical F-value, we need to use the degrees of freedom from the ANOVA table. The degrees of freedom for the between groups and within groups are 2 and 15, respectively.

Using a significance level of α = 0.05, we can find the critical F-value by using an F-distribution table or calculator with degrees of freedom (df) of 2 and 15.

The critical F-value for α = 0.05 and df(2,15) is approximately 3.68.

Therefore, the correct answer is:

3.68