ANOVA - Mean Daily Sales for Jointsoft from Four Modes of Advertising

Jointsoft is a great over-the-counter arthritis medication, but who will ever know about it? Unfortunately, many people with arthritis tend to be elderly and rather immobile, so advertisers of arthritis medications face limitations in ways to get their messages across. Currently, their best modes of advertisement are commercials on daytime TV, advertisements in select magazines, fliers in convalescent homes, and (believe it or not) advertisements on certain Web pages.

Marketing managers for Jointsoft are investigating these four modes of advertisement in four small communities (with a different mode of advertisement in each community). The marketing managers have selected 46 days at random and are looking at the daily sales (in dollars) in each of the communities on eachof these days. Here is what they have to work with:

sample size sample mean sample variance
TV 43 569.6 2090.7
Magazines 43 570.1 2352.1
Fliers 43 570.6 2859.2
Web Pages 43 587.5 1092.1

Suppose that the marketing managers perform a one-way, independent-samples ANOVA test to decide if there are differences in the mean daily sales arising from the four modes of advertisement. (So, they're assuming that the only difference among the four communities is the mode of advertisement used in it.) Such a test uses the statistic

Variation between the samples .

Variation within the samples

For the information in the chart above

1. Give the numerator degrees of freedom F statistic ________
2. Give the denominator degrees of freedom F statistic________
3. Using the 0.05 level of significance, can the marketing managers conclude that the mean daily sales arising from at least one of the modes of advertising differs from the others? Yes or No