Question

A manufacturer knows that their items have a normally distributed length, with a mean of 16 inches, and standard deviation of 2.6 inches.

If one item is chosen at random, what is the probability that it is less than 16.8 inches long?

Answer 1

Solution :

Given that,

mean = = 16

standard deviation = = 2.6

P(X< 16.8) = P[(X- ) / < (16.8-16) /2.6 ]

= P(z <0.31 )

Using z table

probability=  0.6217