7. A study on the enhancing the effect of coffee on long-term memory found that 35 participants given 200 mg of caffeine performed better on a memory test 24 hours later compared to the placebo group that received no caffeine. (3 pts) There was a probability of 0.02 that the difference between the coffee group and the placebo group was due to chance. Are the results of this study statistically significant? Explain. 8. A class consists of 105 women and 60 men. What is the probability that a randomly selected person from the class is a man? (2 pts) 9. A study found that 67% of adults use social networking sites. (6 pts) a) If three adults are randomly selected, what is the probability that all three adults use social networking sites? b) If one adult is randomly selected, what is the probability they do NOT use a social networking site? c) If three adults are randomly selected, what is the probability that at least one of the three people selected uses a social networking site?