HOMEWORK
1.- A large manufacturing firm tests job applicants. Test scores are normally distributed with a mean of 500 and a standard deviation of 50. Management is considering placing a new hire in an upper-level management position if the person scores in the upper sixth percent of the distribution. What is the lowest score a new hire must earn to qualify for a responsible position?
50
625
460
578

2.-An analysis of the grades on the first test in History101 revealed that they approximate a normal curve with a mean of 75 and a standard deviation of 8. The instructor wants to award the grade of A to the upper 10% of the test grades. To the nearest percent, what is the dividing point between an A and a B grade?
80
85
90
95

3.-Suppose a tire manufacturer wants to set a mileage guarantee on its new XB 70 tire. Tests revealed that the tire’s mileage is normally distributed with a mean of 48,300 miles and a standard deviation of 2,050 miles. The manufacturer wants to set the guaranteed mileage so that no more than 5% of the tires will have to be replaced. What guaranteed mileage should the manufacturer announce?
44,918
33,360
50,021
41,322

5.- Suppose a tire manufacturer wants to set a mileage guarantee on its new XB 70 tyre. Tests revealed that the tyre’s mileage is normally distributed with a mean of 48,300 miles and a standard deviation of 2,050 miles. The manufacturer wants to set the guaranteed mileage so that no more than 5% of the tyres will have to be replaced. What guaranteed mileage should the manufacturer announce?
44,918
33,360
50,021
41,322