Using step-deviation method, find mean for the following frequency distribution
Class Frequency
0-15 3
15-30 4
30-45 7
45-60 6
60-75 8
75-90 2
Statistics
ICSE Sp 2025
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Question

Using step-deviation method, find mean for the following frequency distribution Class | Frequency ----- | --------- 0-15 | 3 15-30 | 4 30-45 | 7 45-60 | 6 60-75 | 8 75-90 | 2

KnowledgeBoat · Accepted Answer

In the given table i is the class interval which is equal to 15. Class | Class mark (x) | d = (x - A) |u = d/i | Frequency (f) | fu ---- | ------ | ------ | ------- | -----| -------- 0-15 | 7.5 | -45 | -3 | 3 | -9 15-30 | 22.5 | -30 | -2 | 4 | -8 30-45 | 37.5 | -15 | -1 | 7 | -7 45-60 | A = 52.5 | 0 | 0 | 6 | 0 60-75 | 67.5 | 15 | 1 | 8 | 8 75-90 | 82.5 | 30 | 2 | 2 | 4 Total | | | | Σf = 30 | Σfu = -12 Mean = A + = = 52.5 - 6 = 46.50 Hence, mean = 46.50

Mathematics

Using step-deviation method, find mean for the following frequency distribution
Class Frequency
0-15 3
15-30 4
30-45 7
45-60 6
60-75 8
75-90 2

Statistics

ICSE Sp 2025

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