Chapter 17 Solutions
. 17.1. s/ n = 21.88/ 20 = 4.8925 minutes. . 17.2. The mean is x = 251 ms. Because s/ n = s/ 12 = 45 ms, we have s = 155.88 ms. 17.3. (a) t = 2.015 for df = 5 and = 0.05. (b) t = 2.518 for df = 21 and = 0.01. 17.4. Use df = 24. (a) t
Chapter 16 Solutions
16.1. This is an experiment; students were randomly (at the time they visited the site) assigned to a treatment. The explanatory variable is the login box (genuine or not), and the response is the student's action (logging in or not).
Chapter 15 Solutions
15.1. The most important reason is (c); this is a convenience sample consisting of students with a particular interest in filmmaking which may make their opinions different from those of "typical" college-age adults. Anything we learn
Chapter 14 Solutions
. 14.1. The standard deviation is / 840 = 2.0702. (b) The missing number is (a) . . 2/ 840 = 4.1404. (c) The 95% confidence interval is x 2/ 840 = 268 to 276. 14.2. Shown below are sample output screens for (a) 10 and (b) 1000 SRSs.
Chapter 13 Solutions
13.1. Yes: (1) We have a fixed number of observations (n = 15). (2) It is reasonable to believe that each call is independent of the others. (3) "Success" means reaching a live person, "failure" is any other outcome. (4) Each randomly
Chapter 12 Solutions
12.1. It is unlikely that these events are independent. In particular, it is reasonable to expect that younger adults are more likely than older adults to be college students. Note: Using the notation of conditional probability introd
Chapter 11 Solutions
11.1. Both 283 and 311 pushes per minute are statistics (related to one sample: the subjects with placebo, and the same subjects with caffeine). 11.2. 41% and 37% are parameters (related to the population of all registered voters in F