People gain weight when they take in more energy from food than they expend. Some researchers wanted to investigate the link between obesity and energy spent on daily activity. Choose 20 healthy volunteers who don't exercise. Deliberately choose 10 who are lean and 10 who are mildly obese but still healthy. Attach sensors that monitor the subjects' every move for 10 days. The table below presents data on the time (in minutes per day) that the subjects spent standing or walking, sitting, and lying down. It can be concluded that mildly obese people spend less time standing and walking (on the average) than lean people. Is there a significant difference between the mean times the two groups spend lying down? Use the four-step process to answer this question from the data. (Let₁be the mean time spent lying down by the lean group, and₂be the mean time for the obese group.)

Time (minutes per day) spent in three different postures by lean

and obese subjectsGroupSubjectStand/WalkSitLieLean1514.100365.300553.500Lean2610.925372.512445.650Lean3318.212586.138542.362Lean4588.644356.144494.269Lean5579.869344.994511.081Lean6544.388381.312511.500Lean7676.188271.188471.700Lean8552.656325.219569.006Lean9376.831539.031528.431Lean10508.700526.838398.962Obese11261.244641.281521.044Obese12468.756456.644516.931Obese13364.138577.662568.300Obese14418.667573.662533.208Obese15342.375583.662500.931Obese16414.531567.556453.856Obese17362.650619.262459.550Obese18266.344650.181511.981Obese19406.631571.769446.706Obese20423.356591.369417.919

Find the size, mean and standard deviation n x s Lean Obese

Calculate the test statistic. (Round your answer to three decimal places.)