Question

Question no . 4 of exercise 14.1 class x maths NCERT book

Answer 1

This is the correct answer of your question

Answer 2

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CH 14 STATISTICS

Q.4 Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and summarised as follows. Find the mean heart beats per minute for these women, choosing a suitable method.

$solution$
Sol.       Let the assumed mean, A = 75.5, class interval
                  ui=xi−Ah=xi−75.53
h = 3, so     ui=xi−Ah=xi−75.5
Hence, the mean heart beats per minute for these women is 75.9.