Question

Can someone please answer the following questions with this data set?

1. If we choose an x value at random, remember that this depends on the data, so the x value could be a person or number, is it possible to find if x is usual or unusual? Why? Could you find the probability? What is it?

2. You may also find the confidence interval for the population mean, if your data is quantitative. If your data is qualitative, you may find the confidence interval for the population proportion.

4

5

6

7

7

7

8

8

9

10

10

12

12

14

15

15

16

17

17

19

19

20

20

20

21

21

22

28

32

40

Answer 1

Mean of data-set = 15.367

Standard deviation = 8.331

A value is considered usual if it falls beyond two standard deviations of the mean. This range is:

(u - 2s, u + 2s) = (15.367 - 2*8.331, 15.367 + 2*8.331)

= (-1.295, 32.029)

Only one value fall outside this range which is 40.

Total observations = n = 30

Probability that if a random value is chosen from the given dataset, it will be unusual is: 1/30 = 0.033

b) Confidence interval is calculated in part a) which is:

(-1.295, 32.029)