Pfizer, Inc., a major U.S. pharmaceutical company, is developing a new drug aimed at reducing the pain associated with migraine headaches. Two drugs are currently under development. One consideration in the evaluation of the medication is how long the painkilling effects of the drugs last. A random sample of 12 tests for each drug revealed the following times (in minutes) until the effects of the drug were neutralized.

The random samples are as follows:

Drug A 258 214 243 227 235 222 240 245 245 234 243 211 Drug B 219 283 291 277 258 273 289 260 286 265 284 266

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?