4. Ellie and Alec are each attempting to estimate the proportion of coffee drinkers who consume more than one cup of coffee per day. They each obtain a random sample of coffee drinkers, and, drink more than one cup of coffee per day is 0.40. Ellie and Alec each use their sample data to construct a confidence interval. Ellie's interval is from 0.286 to 0.514, and Alec's interval is from 0.346 to 0.474. One of these intervals was computed correctly, but the other was not. Which interval must be incorrect? each sample, the proportion who A. Ellie's interval must be incorrect. B. Alec's interval must be incorrect. C. It's impossible to answer this question without knowing the level of confidence used for each interval. D. It's impossible to answer this question without knowing the sample sizes. E. It's impossible to answer this question without knowing the sample sizes or the level of confidence used for each interval.

13. A simple random sample of 1100 males aged 12 to 17 in the United States were asked whetherthey played massive multiplayer online role-playing games (MMORPGs); 775 said that they did.We want to use this information to construct a 95% confidence interval to estimate theproportion of all U.S. males aged 12 to 17 who play MMORPGs.Construct a 95% confidence interval to estimate the proportion of 12-to-17 year-old males who play MMORPGs Follow the 4-Step Plan (State, Plan, Do, Conculde)

1. In a study of perception, 110 men are tested and 24 are found to have red/green color blindness (based on data from USA Today).  Assume that this was done in a simple random manner.  A 95% confidence interval estimate of the proportion of all men with red/green color blindness was found to be 0.14 to 0.30.  If we learn that the actual population proportion of men with red/green colorblindness is equal to 0.12, then what can we conclude?    A. The confidence interval was wrong.   B. We would need to see the sample data to make any conclusions Pick either answer A or B as your answer and show your work to go with it

7. A company that has many department stores in the southern states wanted to find at two such stores the percentage of sales for which at least one of the items was returned. A sample of 800 sales randomly selected from Store A showed that for 280 of them at least one item was returned. Another sample of 900 sales randomly selected from Store B showed that for 279 of them at least one item was returned. a. Construct a 98% confidence interval for the difference between the proportions of all sales at the two stores for which at least one item is returned. b. Using the 10% significance level, can you conclude that the proportions of all sales for which at least one item is returned is higher for Store A than for Store B?

8. A confidence interval for estimating the mean An industrial/organizational psychologist wants to improve worker productivity for a client firm, but first he needs to gain a better understanding of the life of the typical white-collar professional. Fortunately, he has access to the 2008 Workplace Productivity Survey, commissioned by LexisNexis and prepared by WorldOne Research, which surveyed a sample of 650 white-collar professionals (250 legal professionals and 400 other professionals). One of the survey questions was, “How many work-related emails do you receive during a typical workday?” For the subsample of legal professionals (n = 250), the mean response was M = 36.7 emails, with a sample standard deviation of s = 23.8 emails.   The estimated standard error is sMM? = A-0.085, B-1.341, C-0.095 or D-1.505 (choices to choose from.)   .   Use the following Distributions tool to develop a 90% confidence interval estimate of the mean number of work-related emails legal…

6.  A researcher takes a sample of people, and asks them how they would vote for president. When she creates her confidence interval, she has a standard error of .082. If she wanted to get a smaller standard error, what could she do? Group of answer choices Ask a different research question. Take a smaller sample. Take a larger sample. None of the above would create a smaller standard error.

11. In professional tennis for 2017 men challenged 2100 calls and 1105 of them were changed. While women challenged 1309 calls and 625 of them were changed. Find a 95% confidence interval for the difference in changed calls for men and women. 12. For problem # 11 conduct a hypothesis test to test the claim that men get more calls changed than women. Use a significance level of .05. 14. Find a 99% confidence interval for the difference in males and females BMI using the following sample data.Female BMI: n=70, mean=29.1, Sx=7.39.Male BMI: n=80, mean=28.38, Sx=5.37.

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