Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and summarized as follows. Find the mean heart beats per minute for these women, choosing a suitable method.
Number of heart beats
per minute $65 - 68$ $68 - 71$ $71 - 74$ $74 - 77$ $77 - 80$ $80 - 83$ $83 - 86$
Number of women $2$ $4$ $3$ $8$ $7$ $4$ $2$

Question

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

Number of heart beats per minute	$65 - 68$	$68 - 71$	$71 - 74$	$74 - 77$	$77 - 80$	$80 - 83$	$83 - 86$
Number of women	$2$	$4$	$3$	$8$	$7$	$4$	$2$

Filo · Accepted Answer

To find the class mark (xi​) for each interval, using the following relation:(xi​)=2Upper  class  limit+Lower  class  limit​Class size, h, of this data =3Considering 75.5 as assumed mean (a),di​,ui​,fi​ui​ are calculated as follows:From the table:∑fi​=30∑fi​ui​=4Mean, xˉ=a+( ∑f i​ ∑fi​ui​ ​ )×h=75.5+4/30×3=75.5+0.4=75.9∴ mean heart beats per minute for these women are 76 beats per minute.

Question Text	Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and summarized as follows. Find the mean heart beats per minute for these women, choosing a suitable method.
Answer Type	Text solution:1
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