Question

The length in time (in years) it took for 32 drinkers to give up alcohol permanently are listed. Assume the population standard deviation is 4.7 years. At α = 0.01, is there enough evidence to reject the claim that the mean time it takes for drinkers to quit drinking permanently is 13 years?

22.6	7.7	17.4	19.1	22.9	20.2	9.2	15.3
16.3	12.3	17.5	16.3	13.1	20.6	19.2	14.5
19.4	12.2	13.3	10.7	18.9	18.8	12.9	21.1
18.4	11.9	8.6	19.8	15.4	14.4	7.6	10.1

a) What are the null and alternate hypotheses?

b) Identify the standardized test statistic (to two decimal places)

c) Find the p-value (to three decimal places)

d) Write a conclusion statement in context with the question.

Answer 1

Solution:

• Conclusion:

There is enough evidence to reject the claim that the mean time it takes for drinkers to quit drinking permanently is 13 years.