TEST A(For Ungrouped Data)

NOTE: This test was taken from the book Introduction to Statistics Third Edition by Ronald E. Walpole.

1. The number of incorrect answers on a true-false competency test for a random sample of 15 students were recorded as follows: 2, 1, 3, 0, 1, 3, 6, 0, 3, 3, 5, 2, 1, 4, and 2. Find a.) the mean; b.) the median; and c.) the mode.

2. The number of building permits issued last month to 12 construction firm in a small Midwestern city were 4, 7, 0, 7, 11, 4, 1, 15, 3, 5, 8, and 7. Treating the data as a population, find a.) the mean; b.) the median; and c.) the mode.

3. The reaction times for a random sample of 9 subjects to a stimulant were recorded as 2.5, 3.6, 3.1, 4.3, 2.9, 2.3, 2.6, 4.1, and 3.4 seconds. Calculate a.) the mean; and b.) the median.

4. The employees of a local manufacturing plant pledged the following donations, in dollars to the United Fund: 10, 40, 25, 5, 20, 10, 50, 30, 10, 5, 15, 25, 50, 10, 30, 5, 25, 45, and 15. Treating the data as a population, calculate a.) the mean; and b.) the mode.

5. According to ecology writer Jacqueline Killeen, phosphates contained in household detergents pass right through our sewer causing lakes to turn into swamps that eventually dry up into deserts. The following data show the amount of phosphates per load of laundry, in grams, for a random sample of various types of detergents used according to the prescribed directions:

Laundry Detergent

Phosphates per Load(gm)

A & P Blue Sail 48Dash 47Concentrated All 42Cold Water All 42Breeze 41Oxydol 34Ajax 31Sears 30Fab 29Cold Power 29Bold 29Rinso 26

TEST B(For Grouped Data)

NOTE: This test was taken from the book Elements of Statistics Third Edition by Elmer B. Mode.

1. The number of cases per year and the mean number of days of in-patients at a cerain hospital are tabulated below. What is the overall mean number of days per patients?

Ward Mean No. of Days No. of Cases

Surgical 20 180

Medical 15 237

Maternity 16 96

Children 14 68

2. The mean hourly rate of pay for each of four industries and the number of employed in each are given below. Compute the overall mean hourly rate.

No. of Employed Rate in Dollars

463,000 1.3

1,328,000 1.42

217,000 2.68

97,000 2.11

3. The weights in milligrams of the dry contents of a certain type of ampul :

Weights Number

80-84 2

85-89 7

90-94 18

95-99 32

100-104 14

105-109 10

110-114 3

115-119 1

120-124 1

Find the mean, median and the mode.

4. A mathematics achievement test contained 40 questions for which the answers were marked either right or wrong. The distribution below summarizes the results. Find the mean, median and the mode.

No. of No. of Answers Correct Frequency

0-2 0

3-5 1

6-8 3

9-11 10

12-14 11

15-17 17

18-20 24

21-23 25

24-26 22

27-29 16

30-32 7

33-35 3

36-40 0

5. Intelligence quotients of runaway boys(from Clairette P. Amstrong 660 Runaway Boys, Richard C. Badger, Gorham Press, Boston, 1932 p. 31). Find the mean, median and the mode.

I.Q. Number

30-39 2

40-49 6

50-59 60

60-69 140

70-79 184

80-89 139

90-99 78

100-109 37

110-119 14