# Question

Suppose that the talk time on the Apple iPhone is approximately normally distributed with mean 7 hours and standard deviation 0.8 hour.

(a) What proportion of the time will a fully charged iPhone last at least 6 hours?

(b) What is the probability a fully charged iPhone will last less than 5 hours?

(c) What talk time would represent the cutoff for the top 5% of all talk times?

(d) Would it be unusual for the phone to last more than 9 hours? Why?

(a) What proportion of the time will a fully charged iPhone last at least 6 hours?

(b) What is the probability a fully charged iPhone will last less than 5 hours?

(c) What talk time would represent the cutoff for the top 5% of all talk times?

(d) Would it be unusual for the phone to last more than 9 hours? Why?

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