## Measures of Central Tendency Exercise

1. For the following scores, find:

(a) The median
(b) The mode
(c) The mean

If using a calculator, remember to clear any earlier numbers that have been entered.

(i) 39, 46, 19, 29, 33, 42, 32, 21, 19

(ii) 901, 999, 900, 998, 901, 904, 996, 991

(iii) 10, 14, 14, 14, 20

(iv) 30.43, 40.92, 10.37, 40.14, 60.64, 81.34, 5.39

 2 A swimmer records the number of lengths he swims each day for a week. The number of lengths are: 30, 55, 62, 64, 60, 82, 30 (a) Calculate the mean, median and mode of these seven numbers. (b) Which of these averages would not be very representative of his week's swimming?

3. A woman has a full-time job and gets paid by the hour. Her weekly pay for 2 months' work was:

\$712.50, \$811.80, \$710.70, \$913.10, \$804.50, \$712.00, \$609.20, \$879.60 and \$695.50

(a) What was her mean weekly pay?

(b) What was her median pay?

4. The table below shows the number of hectares of apples planted in a reion over the past five years.

 Year Number of hectares of apples 1994 10 161 1995 10 210 1996 10 329 1997 10 243 1998 10 015

Find the mean number of acres of kiwifruit planted per year.

5. The results from a small class of students at a high school in French and Spanish are listed below.

a. Find the mean of each set of results.

 French 66 75 89 83 95 81 65 75 69 84 Spanish 46 47 53 54 96 52 56 35 47 47

c. If 10 marks are added to each of the Spanish marks what is the new mean?

 6 a. The mean of fund raising money raised by 30 scouts is \$65 each. What was the total raised by the scouts? b. The total amount of money taken in a pizza shop on a saturday is \$4,400. If 550 pizzas are sold, what is the mean amount each pizza was sold for. c. A group of golfers each played a round of golf for a grand total of 384 shots. If the average round was 96, how many golfers played the round?
 7 A student has an average of 78% in four exams with one exam to go. If he wants to average 80% in the five exams, how many marks will he need in the final exam?