Question

the weights of oranges are normally distributed with a mean weight of 150 grams and a standard deviation of 10 grams. In a sample of 100 oranges, how many will weigh between 130 and 170 grams?

Answer 1

let us consider x is weight of oranges

mean weight 150 grams

and a standard deviation =  10

n= 100

since x~N( 150 ,10)

P(130<x<170) =

P(130<x<170) = = 0.9545 (from z table )

In a sample of 100 oranges, 100*0.9545 = 95.45 ~~96  will weigh between 130 and 170 grams