Psychologists studied the alcohol consumption patterns of people in two age groups. One group consisted of people aged 21 to 35, and the other consisted of people aged 36 to 50. The psychologist interviewed random and independent samples from each group. She assigned scores from 0 to 100 to each individual (a score of 0 meant no alcohol consumption) according to factors such as the frequency and the amount of alcohol consumed. The results from the study are summarized below:
Age 21 to 35: n1 = 28, x̄1 = 55, s1^2 = 225
Age 36 to 50: n2 = 24, x̄2 = 48.8, s2^2 = 148.84
(The first row gives the sample sizes, the second row gives the sample means, and the third row gives the sample variances.)
Assume that the scores of all people aged 21 to 35 are approximately normally distributed. Assume the same for the scores of all people aged 36 to 50. Can we conclude, at the 0.1 significance level, that the variance of the scores of all people aged 21 to 35, σ1^2, is greater than the variance of the scores of all people aged 36 to 50, σ2^2?
Perform a one-tailed test. Then fill in the table below:
The null hypothesis:
H0: σ1^2 ≤ σ2^2
The alternative hypothesis:
H1: σ1^2 > σ2^2
The type of test statistic:
Choose: F
The value of the test statistic: (Round to at least three decimal places.)
The p-value: (Round to at least three decimal places.)
Can we conclude that the variance of the scores of all people aged 21 to 35 is greater than the variance of the scores of all people aged 36 to 50?
Yes