Question: 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. (Calculate critical value to answer this fully)

c. Compute the value of the test statistic. (Show me the values used to calculate test statistic)

d. Formulate the decision rule. (Do you reject H0 or not?)

e. Interpret your decision regarding the null hypothesis?