Reorder point decisions for a particular part at an automotive parts distributor are based on the assumption that weekly demand is normally distributed. ("Reorder point" is the inventory level at which a replenishment order is placed; it should be high enough to cover demand during the order fulfillment period, but low enough to avoid excessive inventory holding costs.) To examine the validity of this assumption, the logistics department has compiled weekly demand values for the past year.

a. Using the Jarque-Bera test, state the competing hypotheses in order to determine whether or not weekly demand values follow the normal distribution.

b. Calculate the value of the Jarque-Bera test statistic. Use Excel to calculate the p-value.

c. At α = 0.05, can you conclude that the weekly demand values are not normally distributed? Is the conclusion sensitive to the choice of significance level?