Question

The data set below shows the number of alcoholic drinks that students at a certain university reported they had consumed in the past month. Complete parts a through c. 13 15 16 17 12 14 17 19 13 13 a. Assume that the data set is a sample. Compute the​ range, variance, standard​ deviation, and interquartile range for the data set.

Answer 1

Range = min to max = 12 to 19

Standard deviation

	Data	(X-average)^2
	12	8.41
	13	3.61
	13	3.61
	13	3.61
	14	0.81
	15	0.01
	16	1.21
	17	4.41
	17	4.41
	19	16.81
Average	14.9
Sum		46.9
Variance=Divide this sum by n-1 =9		5.21
Standard deviation = Sqrt of 5.21		2.28

Inter quartile range:

1. Arrange the data in increasing order
12, 13, 13, 13,14,15,16,17,17,19
2. Find Median = middle most value = 14.5
3. Split the data into two equal halves
4. Q1 = First half, 12, 13, 13, 13,14, now find the Median which is 13
5. Q2 = Second half, 15,16,17,17,19, now find the Median which is 17
6. IQR = Q2-Q1 = 17-13=4