The life span of battery is normally distributed, with mean of 2400 hours and standard deviation of 40 hours. What percent of batteries have the life span that is more than 2470 hours? Would it be unusal for a battery to have life span that is more than 2470 hours? Describe your reasoning

What percent of batteries have a life span which is more than 2470 hours

Approximately ......% of batteries have life span which is more than 2470 hours

Would it be unusal for a battery have a life span that is more than 2470 hours? Describe your reasoning

a. It is unusal  for battery to have life span that is more than 2470 hours because the z-score I s in 2 standard deviations of mean.

b. It is unusal  for battery to have life span that is more than 2470 hours because the z-score Is not in 2 standard deviations of mean.

C. It isn't unusal for battery to have life span that is more than 2470 hours because the z-score Isn't within 2 standard deviations of mean.

d. It isn't unusal for battery to have life span that is more than 2470 hours because the z-score Is  within 2 standard deviations of mean.