Question

Trucks in a delivery fleet travel a mean of 110 miles per day with a standard deviation of 14 miles per day. The mileage per day is distributed normally. Find the probability that a truck drives between 125 and 132 miles in a day. Round your answer to four decimal places.

Answer 1

Solution :

Given that ,

mean = $\mu$ = 110

standard deviation = $\sigma$ = 14

P(125< x < 132) = P[(125-110) /14 < (x - $\mu$ ) / $\sigma$ < (132-110) / 14)]

= P(1.07 < Z <1.57 )

= P(Z <1.57 ) - P(Z < 1.07)

Using z table   

=  0.9418 - 0.8577

probability= 0.0841