A report in 2010 indicates that Americans between the ages of 8 and 18 spend an average of 7.5 hours per day using some sort of electronic device such as smart phones, computers, or tablets. Assume that the distribution is normal with a standard deviation of 2.5 hours. What proportion of people use their electronic devices more than 12 hours a day?

Answer rating: 100% (QA)

Mean 75 hours Standard deviation 25 hours Propo... View the full answer