Question

Using the class intervals 0-9, 10-19, 20-29,..., construct the frequency distribution for: 15, 8, 12, 7, 13, 16, 22, 29, 35, 49, 37 and 48.

Answer 1

Given:

Data set: 15, 8, 12, 7, 13, 16, 22, 29, 35, 49, 37, 48

Class intervals: 0-9, 10-19, 20-29, ...

∴ f_0-9 = 2  [Counting the observations 7 and 8]

∴ f_10-19 = 4  [Counting the observations 12, 13, 15, and 16]

∴ f_20-29 = 2  [Counting the observations 22 and 29]

∴ f_30-39 = 2  [Counting the observations 35 and 37]

∴ f_40-49 = 2  [Counting the observations 48 and 49]

∴ Total Frequency = 2 + 4 + 2 + 2 + 2 = 12  [Summing frequencies to verify against the 12 total data points]

The frequency distribution table is as follows:

Class Interval	Frequency
0 - 9	2
10 - 19	4
20 - 29	2
30 - 39	2
40 - 49	2

∴ The frequencies for classes 0-9, 10-19, 20-29, 30-39, and 40-49 are 2, 4, 2, 2, and 2 respectively.