(a) A repeated-measures study with a sample of n = 9 participants produces a mean difference of M_D = 3 with a standard deviation of s = 6. Based on the mean and standard deviation you should be able to visualize (or sketch) the sample distribution. Use a two-tailed hypothesis test with = .05 to determine whether it is likely that this sample came from a population with _D = 0. (Use 3 decimal places.)

t-critical =

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