**10. Correct. The answer is
true**

First, find standard units (z). Z = [(100)^{2}/125) + (200)^{2}/125]^{(}^{1/2)} = 20 hours

The difference 160 hours in standard units (z) = (160-200)/20 = -2

The required probability = (area under normal curve to right of z = -2)

= (.5000 + .4772 ) =
.9772

The difference 250 hours in standard units (z) = (250-200)/20 = 2.50

The required probability = (area under normal curve to right of z = 2.50)

= (.5000 - .4938) = .0062