The General Social Survey is an annual survey given to a random selection of about 1500 adults in the United States. Among the many questions asked are "What is the highest level of education you've completed?" and "If you're employed full-time, how many hours do you spend working at your job during a typical week?"

In a recent year, 1101 respondents answered both questions. The summary statistics are given in the chart below. (The sample data consist of the times, in hours per week, that were given by the respondents.)

Groups Sample Sample Sample size mean variance Less than h.s. 266 41.4 94.3 High school 296 40.1 113.9 Bachelor's 282 41.7 101.6 Graduate 257 40.9 94.8 Send data to calculator v Send data to Excel To decide if there are any differences in the mean hours per week worked by these different groups, we can perform a one-way, independent-samples ANOVA test. Such a test uses the following statistic. F= Variation between the samples Variation within the samples For the data from the survey, F ~ 1.39. (a) Give the numerator degrees of freedom of this F statistic. X . 5 ? (b) Give the denominator degrees of freedom of this F statistic. (c) From the survey data, can we conclude that at least one of the groups differs significantly from the others in mean hours worked in a typical Yes No week? Use the 0.01 level of significance