A vinyl siding company claims that the meantime to install siding on a medium-size house is at most 20 hours with a standard deviationof 3.7 hours. A random sampleof 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. Formulate the decision rule.
e. What is your decision regarding the null hypothesis? Interpret the result.
The solution provides a step by step method for the calculation of a T test. Formula for the calculation and interpretation of the results are also included.