1.Toby's Trucking Company determined that the distance travelled per truck per year is normally distributed, with a mean of 50 thousand miles and a standard deviation of 12 thousand miles.

a.What proportion of trucks can be expected to travel between 34 and 50 thousand miles in a year?

b.What percentage of trucks can be expected to travel either less than 30 or more than 60 thousand miles in a year?

C. How many miles will be travelled by at least eighty percent of the trucks?