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 259 220 240 224 233 226 242 248 240 238 247 213 Drug B 219 290 295 280 250 276 2 282 264 284 263 288 261 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? 235.83 (Round to two decimal places as needed.) What is the standard deviation of drug A? (Round to three decimal places as needed.)