Question

A particular fruit's weights are normally distributed, with a mean of 760 grams and a standard deviation of 39 grams. The heaviest 8% of fruits weigh more than how many grams? Give your answer to the nearest gram.

Answer 1

Given,

= 760 , = 39

We convert this to standard normal as

P( X < x) = P( Z < x - / )

We have to calculate x such that P( X > x) = 0.08

P( X < x) = 0.92

P( Z < x - / ) = 0.92

From Z table, z-score for the probability of 0.92 is 1.4051

x - / = 1.4051

x - 760 / 39 = 1.4051

x = 815