Kelso Motor Parts produces a car battery with a useful life that has a normal distribution.Average life is 40,000 miles, with a standard deviation of 1500 miles.What proportion of the batteries will have a useful life of more than 43,000 miles?
A).0472
B).0913
C).0367
D).1005
E).0228

Question

Quizplus · Accepted Answer

To find the proportion of batteries with a life of more than 43,000 miles, calculate the z-score: (43,000 - 40,000) / 1,500 = 2. Using the standard normal distribution table, the area to the left of z = 2 is 0.9772. Therefore, the area to the right (proportion of batteries lasting more than 43,000 miles) is 1 - 0.9772 = 0.0228.

Kelso Motor Parts Produces a Car Battery with a Useful