Four brands of baseball bats were tested to determine which…

Four brands of baseball bats were tested to determine which bat allowed hitters to hit a baseball farthest. Eight different batters were thrown 25 pitches while hitting with each of the four bats (assigned in random order). The average distance of the five longest hits using each bat was recorded and is shown in the table below: A randomized block design with brand as the the single factor and batters as the blocking variable was used to analyze the data. The dot-plots and the ANOVA analysis from JMP are given below: The goal is to determine if the average hit distance differs for the four brands of baseball bats. Based on the JMP output, which statement is correct at the 99% confidence level?

Customer satisfaction has been found to drop off dramaticall…

Customer satisfaction has been found to drop off dramatically when customers have to wait more than 2.5 minutes in a check-out lane at the grocery store. A random sample of 64 customers’ wait time yielded a mean time of 2.96 minutes. The standard deviation of the sample was 1.04 minutes. Using alpha = 0.05, we want to test whether the average wait time is significantly greater than 2.5 minutes. What are the correct Hypotheses and the correct test statistic?