Power+, produces AA batteries used in remote-controlled toy cars. The mean life of these batteries follows the normal probability distribution with a mean of 30 hours and a standard deviation of 4.7 hours. As a part of its testing program, Power+ tests samples of 36 batteries. UseAppendix B.1for thez-values.

a.What can you say about the shape of the distribution of sample mean?

Shape of the distribution is

(Click to select)

Normal

Uniform

Binomial

b.What is the standard error of the distribution of the sample mean?(Round the final answer to 4 decimal places.)

Standard error

c.What proportion of the samples will have a mean useful life of more than 31 hours?(Round the finalanswer to 4 decimal places.)

Probability

d.What proportion of the sample will have a mean useful life greater than 29.5 hours?(Round the final answerto 4 decimal places.)

Probability

e.What proportion of the sample will have a mean useful life between 29.5 and 31 hours?(Round the finalanswer to 4 decimal places.)

Probability