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 (d) below. Question content area bottom Part 1 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.) Part 2 b. What percentage of trucks can be expected to travel either less than 40 or more than 65 thousand miles in a year? The percentage of trucks that can be expected to travel either less than 40 or more than 65 thousand miles in a year is %. (Round to two decimal places as needed.) Part 3 c. How many miles will be traveled by at least 60% of the trucks? The number of miles that will be traveled by at least 60% of the trucks is miles. (Round to the nearest mile as needed.) Part 4 d. What are your answers to parts (a) through (c) if the standard deviation is 7 thousand miles? If the standard deviation is 7 thousand miles, 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.) Part 5 If the standard deviation is 7 thousand miles, the percentage of trucks that can be expected to travel either less than 40 or more than 65 thousand miles in a year is %. (Round to two decimal places as needed.) Part 6 If the standard deviation is 7 thousand miles, the number of miles that will be traveled by at least 60% of the trucks is miles.