Question

a) Make a frequency distribution table.Make a frequency distribution table with 6 classes on the following test scores of 25 students in my class. Include the following columns in the table: Classes, Frequency, Class Mark, Class Boundaries, Relative Frequency and Relative % (make sure you find the class width) 45, 67, 87, 96, 76, 56, 45, 56, 67, 77, 88, 92, 34, 37, 46, 86, 90, 96, 49, 50, 60, 70, 85, 70, 99

b) Use the test scores in question 3 to find the mean, median, mode and range. You may use your calculate. You can round to the nearest tenth.(one number after decimal point)

Answer 1

(a)

The frequency distribution table. is made as follows:

Classes	Class width	Frequency	Class mark	Class boundaries	Relative frequency	Relative %
30-41	11	2	35.5	29.5-41.5	2/25 = 0.08	0.08 X100 =8%
42-53	11	5	47.5	41.5-53.3	5/25 =0.20	0.20X 100= 20%
54-65	11	3	59.5	53.5-65.5	3/25 =0.12	0.12X 100 = 12%
66-77	11	6	71.5	65.5-77.5	6/25 =0.24	0.24 X 100 = 24%
78-89	11	4	83.5	77.5-89.5	4/25 =0.16	0.16 X 100 = 16%
90-101	11	5	95.5	89.5-101.5	5/25 =0.20	0.20X100 = 20%
Total =		25			1.00	100%

(b)

(i)

Mean () is given by:

So,

Mean = 69.0

(Round to the nearest tenth)

(ii)

Median is got as follows:
Arranging numbers in ascending order, we get:

34,37,45,45,46,49,50,56,56,60,67,67,70,70,76,77,85,86,87,88,90,92,96,96,99

Median is (25+1)/2th item = 13th item = 70

So,

Median =70.0

(iii)

Since 5 values occur 2 times, there is no mode for this data set.

(iv)

Range = Maximum - minimum = 99 - 34 = 65

So,

Range = 65.0