Question

Trucks in a delivery fleet travel a mean of 110 miles per day with a standard deviation of 38 miles per day. The mileage per day is distributed normally. Find the probability that a truck drives between 132 and 159 miles in a day.

Answer 1

Answer: 0.1824

Step-by-step explanation:

Given : The mileage per day is distributed normally with

Mean : $\mu=110\text{ miles per day}$

Standard deviation :  $\sigma=38\text{ miles per day}$

Let X be the random variable that represents the distance traveled by truck in one day .

Now, calculate the z-score :-

$z=\dfrac{x-\mu}{\sigma}$

For x= 132 miles per day.

$z=\dfrac{132-110}{38}\approx0.58$

For x= 159 miles per day.

$z=\dfrac{159-110}{38}\approx1.29$

Now by using standard normal distribution table, the  probability that a truck drives between 132 and 159 miles in a day will be :-

$P(132$

Hence, the probability that a truck drives between 132 and 159 miles in a day =0.1824