Originally Posted by

**Skoz** I did these questions but im not sure if they are 100% correct since the back of the book is not showing the same answers (my teacher said the book could be wrong alot of the time).

3. Calculate the standard deviation for the following:

(17,18, 19, 20, 21, 22, 23, 24, 25, 26)

Mr F says: 3.028. (It's possible your book might give 2.872)

5. Find the quartile values, the interquartile range, and the standard deviation of the salaries listed below.

Salary Frequency

28000 4

30000 6

32000 7

34000 4

36000 2

38000 1

Mr F says:Q1 = 30000, Q2 = 32000, Q3 = 34000, IQR = Q3 - Q1, sd = 2722.69 (it's possible your book might give 2665.36)