Atrucking company determined that the distance traveled per truck per year is normally distributed, with a mean of 80 thousand miles and a standard deviation of 12 thousand miles. Complete parts (a) through (d) below. a. What proportion of trucks can be expected to travel between 64 and 80 thousand miles in a year? The proportion of trucks that can be expected to travel between 64 and 80 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 70 or more than 95 thousand miles in a year? The percentage of trucks that can be expected to travel either less than 70 or more than 95 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 number of miles that will be traveled by at least 75% of the trucks is miles. (Round to the nearest mile as needed.)