## Question 563:

A vinyl siding company claims that the mean time to install siding on a medium-size house is at most 20 hours with a standard deviation of 3.7 hours. A random sample of 40 houses sided in the last three years has a mean installation time of 20.8 hours. At the 0.05 significance level, can a claim be made that it takes longer on average than 20 hours to side a house?a. State the null and alternate hypotheses.

b. State the decision rule.

c. Compute the value of the test statistic.

d. What is your decision regarding the null hypothesis? Interpret the result.

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