Statistics Class Question

Question

A particular fruit's weights are normally distributed, with a mean of 661 grams and a standard deviation of 15 grams.

If you pick one fruit at random, what is the probability that it will weigh between 609 grams and 649 grams

Answer 1

Prob ( 609 < x < 649) =

Prob ( (609-661)/15 < z < (649-661)/15 )

Prob ( -52/15 < z < 12/15)

Prob ( -3.46 < z < 0.8) =

Prob ( z < 0.8) - Prob ( -3.46 < z) =

0.788145 - 0.000263

0.787882 < 78.8%