A study was designed to see what type of incentive might be most effective in encouraging people to exercise. The goal for each of the overweight participants in the study was to walk 7000 steps a day. The study lasted 100 days and the number of days that each participant met the goal was recorded. The participants were randomly assigned to one of four different incentive groups: for each day they met the goal, participants in the first group got only an acknowledgement, participants in the second group got entered into a lottery, and participants in the third group received cash (about $1.50 per day). In the fourth group, participants received all the money up front and lost money (about $1.50 per day) if they did not meet the goal. The success rate was almost identical in the first three groups (in other words, giving cash did not work much better than just saying congratulations) and the mean number of days meeting the goal for these participants was 33.7. For the participants who would lose money, however, the mean number of days meeting the goal was 45.0. (People really hate to lose money!) Test to see if this provides evidence of a difference in means between those losing money and those with other types of incentives, using the fact that the standard error for the difference in means is 4.14.