A Researcher Would Like to Examine How the Chemical Tryptophan,contained

Short Answer

A researcher would like to examine how the chemical tryptophan,contained in foods such as turkey,can affect mental alertness.A sample of n = 9 college students is obtained,and each student's performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roast turkey.The average score dropped by MD = 14 points after the meal with SS = 1152 for the difference scores.
a.Is there is significant difference in performance before eating versus after eating? Use a two-tailed test with α = .05.
b.Compute r² to measure the size of the effect.