A random sample of 12 tests for two different drugs revealed the following times (in minutes) until the effects of the drug were neutralized. Drug A 214 280 298 279 258 270 280 262 289 269 286 261 Drug B 251 217 246 226 236 227 248 250 246 231 245 217 a. Calculate the mean and standard deviation for each of the two drugs. b. Based on the sample means calculated in part a, which drug appears to be effective longer? c. Based on the sample standard deviations calculated in part a, which drug appears to have the greater variability in effect time? d. Calculate the sample coefficient of variation for the two drugs. Based on the coefficient of variation, which drug has the greater variability in its time until the effect is neutralized? a. What is the mean of drug A? (Round to two decimal places as needed.)