Question

100 surnames were randomly picked up from a local telephone directory and the frequency distribution of the number of letters in the English alphabets in the surnames was obtained as follows: Find the mean number of letters in the surnames.

Number of letters
1-4
4-7
7-10
10-13
13-16
16-19
Number of surnames
6
30
40
16
4
4

Answer 1

Answer:

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