1. Statistics: Unlocking the Power of Data Lock 5 Section 4.5 Confidence Intervals and Hypothesis Tests

2. Statistics: Unlocking the Power of Data Lock 5 Review a) 0.5 b) 0.54 c) 20 Randomization distributions are always centered around the null hypothesized value.

3. Statistics: Unlocking the Power of Data Lock 5 Which Distribution? (a) is centered around the sample statistic, 6.7

4. Statistics: Unlocking the Power of Data Lock 5 Which Distribution? Intro stat students are surveyed, and we find that 152 out of 218 are female. Let p be the proportion of intro stat students at that university who are female. A bootstrap distribution is generated for a confidence interval for p, and a randomization distribution is generated to see if the data provide evidence that p > 1/2. Which distribution is the randomization distribution? (a) is centered around the null value, 1/2

5. Statistics: Unlocking the Power of Data Lock 5 Both Father and Mother “Does a child need both a father and a mother to grow up happily?” Let p be the proportion of adults aged 18-29 in 2010 who say yes. A 95% CI for p is (0.487, 0.573). Testing H 0 : p = 0.5 vs H a : p ≠ 0.5 with α = 0.05, we a) Reject H 0 b) Do not reject H 0 c) Reject H a d) Do not reject H a 0.5 is within the CI, so is a plausible value for p. http://www.pewsocialtrends.org/2011/03/09/for- millennials-parenthood-trumps-marriage/#fn-7199-1

6. Statistics: Unlocking the Power of Data Lock 5 Both Father and Mother “Does a child need both a father and a mother to grow up happily?” Let p be the proportion of adults aged 18-29 in 1997 who say yes. A 95% CI for p is (0.533, 0.607). Testing H 0 : p = 0.5 vs H a : p ≠ 0.5 with α = 0.05, we a) Reject H 0 b) Do not reject H 0 c) Reject H a d) Do not reject H a 0.5 is not within the CI, so is not a plausible value for p. http://www.pewsocialtrends.org/2011/03/09/for- millennials-parenthood-trumps-marriage/#fn-7199-1

7. Statistics: Unlocking the Power of Data Lock 5 Interval, Test, or Neither? Is the following question best assessed using a confidence interval, a hypothesis test, or is statistical inference not relevant? On average, how much more do adults who played sports in high school exercise than adults who did not play sports in high school? a) Confidence interval b) Hypothesis test c) Statistical inference not relevant

8. Statistics: Unlocking the Power of Data Lock 5 Interval, Test, or Neither? Is the following question best assessed using a confidence interval, a hypothesis test, or is statistical inference not relevant? Do a majority of adults riding a bicycle wear a helmet? a) Confidence interval b) Hypothesis test c) Statistical inference not relevant

9. Statistics: Unlocking the Power of Data Lock 5 Interval, Test, or Neither? Is the following question best assessed using a confidence interval, a hypothesis test, or is statistical inference not relevant? On average, were the 23 players on the 2010 Canadian Olympic hockey team older than the 23 players on the 2010 US Olympic hockey team? a) Confidence interval b) Hypothesis test c) Statistical inference not relevant