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 214 282 290 273 257 270 285 268 287 268 287 261 Drug B 259 213 250 230 235 228 245 248 247 237 245 219 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.)