Question

The accompanying data on food intake (in Kcal) for 15 men on the day following two nights of only 4 hours of sleep each night and for 15 men on the day following two nights of 8 hours of sleep each night is consistent with summary quantities in the paper "Short-Term Sleep Loss Decreases Physical Activity under Free-Living Conditions But Does Not Increase Food Intake under Time Deprived Laboratory Conditions in Healthy Men" (American Journal of Clinical Nutrition [2009]: 1476–1482). The men participating in this experiment were randomly assigned to one of the two sleep conditions.

4-hour sleep group:	3585	4470	3068	5338	2221
	4791	4435	3099	3187	3901
	3868	3869	4878	3632	4518
8-hour sleep group:	4965	3918	1987	4993	5220
	3653	3510	3338	4100	5792
	4547	3319	3336	4304	4057

Verify the assumption of approximate normality for each of the populations. Carry out a two-sample t test with α = 0.05 to determine if there is a significant difference in mean food intake for the two different sleep conditions. (Use a statistical computer package to calculate the P-value. Use μ_4-hour − μ_8-hour. Round your test statistic to two decimal places, your df down to the nearest whole number, and your P-value to three decimal places.)

t	=
df	=
P-value	=

Answer 1