Weekly wages at a certain factory are
normally distributed with a mean of
$400 and a standard deviation of $50.
find the probability that a worker
selected at random makes between
$300 and $350.

0.1359

Step-by-step explanation:

mean = $400

Standard deviation = $50

Since the wages is normally distributed , the first thing is to find the z - score.

z =

finding the z - value for 300 and 350 , we have

z =

z =

2 = -2

also

z =

z =

z = -1

The next thing is to check the calculated value on z - table.

From z - table :

P (z -2 ) = 0.0228

P ( z ) = 0.1587

combining the two

P ( -2z-1 ) = 0.1587 - 0.0228

P ( -2z-1 ) = 0.1359

Therefore , the the probability that a worker

selected at random makes between

$300 and $350 = 0.1359