Frequency 242 2 244 5 3. (Analysis of variance - Ch 7.5 - 8 points) A double-blind experiment was carried out to investigate the effect of caffeine on performance of a simple physical task. 30 male college students were trained in finger tapping. They were then divided at random into 3 groups of 10, and each group was given a different dose of caffeine (0, 100 and 200 mg). Two hours after the dose, each man was required to do finger tapping and the number of taps per minute (`rate`) was recorded. Does caffeine affect performance of this task? To answer this question, use the R output for an analysis of variance below. Histograms of the data are also provided, which can be used to check the assumption of roughly normal data and equal variances. Organize your answer following the 5-step procedure for testing a hypothesis. In step 4 (test statistic and p-value) you do not need to do any calculations. You can get the p-value from the R output. Df Sum Sq Mean Sq F value dose 2 61.4 Residuals 27 134.1 Pr(>F) 30.700 6.181 0.00616 ** 4.967 Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 .' 0.1' 1 No Caffeine Frequency 3 100 mg Caffeine Frequency 200 mg Caffeine 246 248 250 252 242 244 246 248 250 252 242 244 246 248 250 252 Taps per minute Taps per minute Taps per minute