Question

"The weights of 1,000 children, in average, is 62kg with a standard deviation of 16kg. Suppose the weights are normally distributed, how many children weigh less than 51kg?"

Answer 1

Given : mean= 62

sd = 16

formula Z= $\frac{x-mean}{sd}$

solution:

For x= 51, Z= $\frac{51-62}{16}$ = -0.6875

Using Z table , Pr(Z≤−0.6875)=0.2459

Hence number of children = 1000*0.2459= 245.9 approximately 246 children