A recent study found that the death rate for people who sleep 6 to 7 hours per night is
lower than the death rate for people who sleep 8 or more hours.
The 1.1 million observations used for this study came from a random survey of
Americans aged 30 to 102. Each survey respondent was tracked for 4 years.
The death rate for people sleeping 7 hours was calculated as the ratio of the number of
deaths over the span of the study among people sleeping 7 hours to the total number of
survey respondents who slept 7 hours. This calculation was then repeated for people
sleeping 6 hours, and so on.
Would you recommend that Americans who sleep 9 hours per night consider
reducing their sleep to 6 or 7 hours if they want to prolong their lives? Why or why
not? Explain.