The goal of a study conducted by Meshack and Norman (A-29) was to evaluate the effects of weights on postural hand tremor related to self-feeding in subjects with Parkinson’s disease (PD). Each of the 16 subjects had the tremor amplitude measured (in mm) under three conditions: holding a built-up spoon (108 grams), holding a weighted spoon (248 grams), and holding the built-up spoon while wearing a weighted wrist cuff (470 grams). The data are displayed in the following table.

Tremor Amplitude (mm)

Subject Built-Up Spoon Weighted Spoon Built-Up Spoon þ Wrist Cuff 1 .77 1.63 1.02 2 .78 .88 1.11 3 .17 .14 .14 4 .30 .27 .26 5 .29 .27 .28 6 1.60 1.49 1.73 7 .38 .39 .37 8 .24 .24 .24 9 .17 .17 .16 10 .38 .29 .27 11 .93 1.21 .90 12 .63 .52 .66 13 .49 .73 .76 14 .42 .60 .29 15 .19 .21 .21 16 .19 .20 .16 Can one conclude on the basis of these data that the three experimental conditions, on the average, have different effects on tremor amplitude? Let a ¼ :05. Determine the p value.