A trucking company determined that the distance traveled per truck per year is normally? distributed, with a mean of 40 thousand miles and a standard deviation of 12thousand miles. Complete parts? (a) through? (c) below.
a. What proportion of trucks can be expected to travel between 23and 40 thousand miles in a? year?
The proportion of trucks that can be expected to travel between 23 and 40 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 than25 or more than60 thousand miles in a? year?
The percentage of trucks that can be expected to travel either less than 25 or more than 60 thousand miles in a year is __________%.
?(Round to two decimal places as? needed.)
c. How many miles will be traveled by at least 75?% of the? trucks?
The amount of miles that will be traveled by at least 75?% of the trucks is ______________ miles.
?(Round to the nearest mile as? needed.)