Question

There are 50 boxes in a factory. Their weights, w kg, are divided into 5 classes, as shown in the following table.
Class Weight (kg) # of boxes
A 9.6≤w<18.5 7
B 18.5≤w<27.5 12
C 27.5≤w<36.5 13
D 36.5≤w<45.5 10
E 45.5≤w<54.5 8

B) There are x boxes in the factory marked “fragile”. They are all in class E. The estimated mean weight of all the other boxes in the factory is 30kg. Calculate the value of x.

Answer 1

You can do the mean calculation as follows.
use the 'midpoint' of each subinterval
14*7/(50-x) + 23*12/(50-x) + 32*13/(50 -x ) + 41* 10/(50-x) + 50*(8-x)/(50-x) = 30

Answer 2

hi

Answer 3

hey kiity