CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Thirty women were examined in a hospital by a doctor and the number of heart beats per minute recorded and summarised as follows. Find the mean heat beats per minute for these women, choosing a suitable method.
Number of heart beats per minute: 65-58 68-71 71-74 74-77 77-80 80-83 83-86
Number of women: 2 4 3 8 7 4 2

Open in App
Solution

Let the assumed mean be A = 75.5 and h = 3.

No. of Heart Beats per Min: Mid Value xi No. of Women fi: di=xi-A ui=1h×di fiui
65-68 66.5 2 -9 -3 -6
68-71 69.5 4 -6 -2 -8
71-74 72.5 3 -3 -1 -3
74-77 75.5 = A 8 0 0 0
77-80 78.5 7 3 1 7
80-83 81.5 4 6 2 8
83-86 84.5 2 9 3 6
fi=30 fiui=4

We know that mean,

Now, we have.

Putting the values in the above formula, we have




Hence, the mean heart beats per minute for women is 75.9.


flag
Suggest Corrections
thumbs-up
90
similar_icon
Similar questions
View More
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Function of The Heart
BIOLOGY
Watch in App
Join BYJU'S Learning Program
CrossIcon