Loading....

JAMB UTME - Mathematics - 1984

Question 1 Report

Measurements of the diameters, in centimeters, in centimeters, of 20 copper spheres are distributed as shown below:

Class boundary in cm frequency
3.35 − 3.45 3
3.45 − 3.55 6
3.55 − 3.65 7
3.65 − 3.75 4

What is the mean diameter of the copper spheres?

Answer Details
x(mid point) f f x 3.4 3 10.2 3.5 6 21.0 3.6 7 25.2 3.7 4 14.8
∑ f  = 20
∑ f x  = 71.2
mean =  ∑ f x ∑ f
=  71.2 20
= 3.56