In the article "Are Christian/Religious People Poor Tippers?" (Journal of Applied Social Psychology, Vol. 43, Issue 5, pp. 928-935), M. Lynn and B. Katz report that, for customers who receive bad service, the mean percentage tip is 8.56% of the bill with a standard deviation of 5.37%. Let x represent the percentage of the bill that a customer tips when he or she receives bad service.
a. What percentage of tips for bad service are at least 0%?
b. Assuming that x is approximately normally distributed, use normal curve areas to determine the approximate percentage of tips for bad service that are at least 0%.
c. Based on your results from parts (a) and (b), do you think that the percentage of the bill that a customer tips when he or she receives bad service is approximately a normally distributed variable? Explain your answer.