TABLE 12-12
Recent studies have found that American children are more obese than in the past. The amount of time children spent watching television has received much of the blame. A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television. We are interested in testing whether the average number of hours spent watching TV and weights are independent at 1% level of significance.

-Referring to Table 12-12, the degrees of freedom of the test statistic are
A) 1
B) 2
C) 4
D) 9

Question

TABLE 12-12
Recent studies have found that American children are more obese than in the past. The amount of time children spent watching television has received much of the blame. A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television. We are interested in testing whether the average number of hours spent watching TV and weights are independent at 1% level of significance.
 
-Referring to Table 12-12, the degrees of freedom of the test statistic are
A) 1 
B) 2 
C) 4 
D) 9

Quizplus · Accepted Answer

The degrees of freedom for a test statistic in a chi-square test are calculated as the number of categories minus one. If Table 12-12 refers to a chi-square test with 5 categories, then the degrees of freedom would be 5 - 1 = 4.

TABLE 12-12 Recent Studies Have Found That American Children Are More Obese