## Chapter 8, Lesson 3

Here's how Will found the mean for 16, 18, 22, 24, 23:

Step 1: He assumed the mean to be 20.

Step 2: He found the difference between his assumed mean and each

individual score, noting higher and lower than the mean.

16 ? —4, 18 ? —2 , 22 ? +2, 24 ? +4, 23 ? +3 and added

all the differences, —4 +(—2) + 2 + 4 + 3 = +3

Step 3: He divided that sum by the number of scores, +3 ÷ 5 = +0.6,

and adjusted his assumed mean, 20 + 0.6 = 20.6

a. Use the method of an assumed mean to find the mean of this data set: 672, 686, 684, 679, 675. Tell the mean you assumed.

b. Verify your result by the usual method for finding the mean.

c. Which method did you prefer for this data set? Explain.