=+13. Young people may feel they are carrying the weight of the world on their shoulders when in reality they are too often carrying an excessively heavy backpack. The article “Effectiveness of a School-Based Backpack Health Promotion Program” (Work, 2003: 113–123) reported the following data for a sample of 131 sixth graders: for backpack weight

(lbs), x 5 13.83, s 5 5.05; for backpack weight as a percentage of body weight, a 95% CI for the population mean was (13.62; 15.89).