Share
Explore BrainMass

Statistics

Talk Time on a Cell Phone: Suppose the 'talk time' in digital mode on a Motorola Timeport P8160 is
normally distributed with mean 324 minutes and standard deviation 24 minutes.

(a) What percent of the time will a fully charged battery last at least 330 minutes?
(b) What is the probability that a random sample of n = 15 batteries results in a mean talk time
of at least 330 minutes?
(c) What is the probability that a random sample of n = 30 batteries results in a mean talk time
of at least 330 minutes?

Solution Preview

mu = 324, sigma = 24

(a) x = 330

z = (x - mu)/sigma = (330 - 324)/24 = 0.25

P(x >= 330) = ...

Solution Summary

A Complete, Neat and Step-by-step Solution is provided.

$2.19