# Hypothesis test for the population mean: Z test

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A leasing firm claims that mean number of miles driven annually, mu, in its leased cars is less than 12480 miles. A random sample of 16 cars a leased from this firm had a mean of 11075 annual miles driven. It is known that the population standard deviation of the number of miles driven in cars from this firm is 2820 miles. Assume that the population is normally distributed. Is there support for the firm's claim at the 0.05 level of significance?

Perform a one-tailed test. Then fill in the table attached.

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#### Solution Preview

H0: mu = 12480 miles

HA: mu < 12480 miles

Type of test statistic = t

p-value = 0.0324

Conclusion: Since the p-value is less than ...

#### Solution Summary

The solution performs a one tailed test and calculates the relevant statistics for a leasing firm.