Dr. Richard Hurt and his colleagues (Hurt et al., 1994) randomly assigned volunteers wanting to quit smoking to wear either a nicotine patch or a placebo patch to determine whether wearing a nicotine...

Dr. Richard Hurt and his colleagues (Hurt et al., 1994) randomly assigned volunteers wanting to quit smoking to wear either a nicotine patch or a placebo patch to determine whether wearing a nicotine patch improves the chance of quitting. After 8 weeks of use, 46% of those wearing the nicotine patch but only 20% of those wearing the placebo patch had quit smoking.

a. Was this a randomized experiment or an observational study?

b. The difference in the percentage of participants who quit (20% versus 46%) was statistically significant. What conclusion can be made on the basis of this study?

c. Why was it advisable to assign some of the participants to wear a placebo patch?