Question

CNN/Money reports that the mean cost of a speeding ticket, including court fees, was $150.00 in 2002. A local police department claims that this amount has increased. To test their claim, they collected data from a simple random sample of 145 drivers who have been fined for speeding in the last year and found that they paid a mean of $155.00 per ticket.

Assuming that the population standard deviation is $17.30, is there sufficient evidence to support the police department’s claim at ? = 0.05 significance level?

a) Identify the null hypothesis and the alternative hypothesis.

b) Is the test two-tailed, left-tailed, or right-tailed?

c) What is the value of the test statistic?

d) What is the P-value?

e) What is the critical value?
f) Is there significant evidence to support the claim?

Answer 1