Question

A trucking company determined that the distance traveled per truck per year is normally​ distributed, with a mean of 50 thousand miles and a standard deviation of 10 thousand miles. Complete parts​ (a) through​ (b) below.

a. What proportion of trucks can be expected to travel between 37 and 50 thousand miles in a​ year?

The proportion of trucks that can be expected to travel between 37 and 50 thousand miles in a year is__.

​(Round to four decimal places as​ needed.)

b. What percentage of trucks can be expected to travel either less than 30 or more than 65 thousand miles in a​year?

The percentage of trucks that can be expected to travel either less than 30 or more than 65 thousand miles in a year is__.

​(Round to two decimal places as​ needed.)

c. How many miles will be traveled by at least 80​% of the​ trucks?

The number of miles that will be traveled by at least 80​% of the trucks is nothing miles.

​(Round to the nearest mile as​ needed.)

D. What are your answers to parts​ (a) through​ (c) if the standard deviation is 8 thousand​ miles?

If the standard deviation is 8 thousand​ miles, the proportion of trucks that can be expected to travel between 37 and 50 thousand miles in a year is nothing.

​(Round to four decimal places as​ needed.)

Answer 1