Sixteen college freshmen were asked to record the number of alcoholic drinks they typically consume in a week.Here are their data: 2, 4, 6, 0, 1, 10, 9, 0, 6, 3, 6, 8, 5, 4, 6, 2.What is the variance of the number of alcoholic drinks consumed per week?
A) 2.96
B) 3.26
C) 8.75
D) 12.25

Question

Quizplus · Accepted Answer

1. Find the mean: sum of data / number of data = (2+4+6+0+1+10+9+0+6+3+6+8+5+4+6+2) / 16 = 4.8125.
2. Find deviations from the mean for each data: subtract the mean from each data. For example, the deviation from the mean for the first data (2) is 2 - 4.8125 = -2.8125. Do this for all data.
3. Square each deviation. For example, (-2.8125)^2 = 7.91015625. Do this for all deviations.
4. Find the sum of squared deviations: sum of all squared deviations = 100.5.
5. Divide the sum of squared deviations by the number of data to get the variance: 100.5 / 16 = 6.28125.
Therefore, the variance is 6.28125, which is closest to choice C (8.75).

Sixteen College Freshmen Were Asked to Record the Number of Alcoholic