Many factors affect the number of automobile accidents on major highways, for example, increased traffic, weather conditions, and driver fatigue. A recent study was conducted to determine whether the...

Many factors affect the number of automobile accidents on major highways, for example, increased traffic, weather conditions, and driver fatigue. A recent study was conducted to determine whether the frequency of median crashes is related to the number of lanes and/or the differential elevation or opposite travel lanes. Independent random samples of U.S. highways were obtained for each combination of lanes and differential elevation. The number of median crashes over a 6-month time period was recorded for each. Construct a two-way ANOVA table. Interpret the results. Use a = 0.05 for each hypothesis test.

Approximately 437 nuclear power plants are in operation around the world, with an estimated power production of 372,210 MWh per year.17 Independent random samples of nuclear power plants in three countries were obtained, and the net generating capacity per year (in MW) of each was obtained. Summary statistics are given in the following table.