Question

Weekly wages at a certain factory are

Answer 1

Answer: 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 = $\frac{x-mean}{standard deviation}$

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

z = $\frac{300-400}{50}$

z = $\frac{-100}{50}$

2 = -2

also

z = $\frac{350-400}{50}$

z = $\frac{-50}{50}$

z = -1

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

From z - table :

P (z$\leq$ -2 ) = 0.0228

P ( z $\leq -1$ ) = 0.1587

combining the two

P ( -2$\leq$z$\leq$-1 ) = 0.1587 - 0.0228

P ( -2$\leq$z$\leq$-1 ) = 0.1359

Therefore , the the probability that a worker

selected at random makes between

$300 and $350 = 0.1359