A supplier of highway construction materials claims he can supply an asphalt mixture that will make roads that are paved with his materials less slippery when wet. A general contractor who builds roads wishes to test the supplier’s claim. The null hypothesis is “Roads paved with this asphalt mixture are no less slippery than roads paved with other asphalt.” The alternative hypothesis is “Roads paved with this asphalt mixture are less slippery than roads paved with other asphalt.”
a. Describe the meaning of the two possible types of errors that can occur in the decision when this hypothesis test is completed.
b. Describe how the null hypothesis, as stated previously, is a “starting point” for the decision to be made about the asphalt.