The mean useful life of car batteries is 55 months. They have a standard deviation of 2. Assume the useful life of batteries is normally distributed. a. Calculate the percent of batteries with a useful life of less than 51 months. (Round your answer to the nearest hundredth percent.) b. Calculate the percent of batteries that will last longer than 61 months. (Round your answer to the nearest hundredth percent.) a. Percent of batteries % b. Percent of batteries %

a. 0.13% b. 2.28%

Step-by-step explanation:

Let x denotes the useful life of batteries.

Given: months,

Since X is normally distributed.

The probability that batteries with a useful life of less than 38 months

The percent of batteries with a useful life of less than 38 months =0.13%

The probability that batteries will last longer than 68 months

The percent of batteries that will last longer than 68 months =2.28%

Step-by-step explanation:

blue marble is 15 times out of 50 = 15/50 reduces to 3/10

landing on tails is 24 out of 50 = 24/50 reduces to 12/25

to find the probability of both multiply together:

3/10 x 12/25 = 3 x 12 / 10 x 25 = 36/250

if you multiplied the numerator and denominator by 10 you get 360/2500.

the answer is 360/2500

a

step-by-step explanation: