A group of researchers is studying the effects of a new diet on cholesterol levels in high-risk patients. The researchers had hypothesized that the cholesterol level would be reduced to a safe level in more than 70% of subjects following the new diet. They are confident that the proportion will be no less than 0.70. To test this one-sided hypothesis, they randomly sampled 200 individuals with dangerously high cholesterol and put them on the new diet. After the period of the study, the researchers determined that 150 of the 200 patients sampled had reduced their cholesterol levels while on the new diet. Find the power of the study. Assume that the significance level is 0.10.

Tourism is extremely important to the economy of Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity (Orlando Sentinel, May 19, 2018). Hotel occupancy data for February in two consecutive years are as follows. Current Year 1,394 1,700 Occupied Rooms Total Rooms a. Formulate the hypothesis test that can be used to determine whether there has been an increase in the proportion of rooms occupied over the one-year period. Let p₁ = population proportion of rooms occupied for current year P2 = population proportion of rooms occupied for previous year 0.82 Previous Year 1,404 1,800 Ho: P1 P2 less than or equal to 0 Ha P₁ P2 greater than 0 b. What is the estimated proportion of hotel rooms occupied each year (to 2 decimals)? Current year Previous Year c. Conduct a hypothesis test. What is the p-value (to 4 decimals)? Use Table 1 from Appendix B. 0.78

In an observational study it was found that people who had received the flu shot this year had better blood pressure readings, on average, than people who did not.  Can it be claimed that the flu shot is the cause of the lower overall blood pressure?  Why or why not?

A scientist is studying the effect of a new type of exercise program on cardiovascular health. The scientist randomly assigns individuals to either the exercise program or a control group. The scientist wants to determine if the exercise program has a statistically significant effect on cardiovascular health. The scientist monitors cardiovascular health by measuring the blood pressure of each individual.

Tourism is extremely important to the economy of Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity (Orlando Sentinel, May 19, 2018). Hotel occupancy data for February in two consecutive years are as follows. Current Year 1,476 1,800 Occupied Rooms Total Rooms 1,422 1,800 a. Formulate the hypothesis test that can be used to determine whether there has been an increase in the proportion of rooms occupied over the one-year period. Let P₁= population proportion of rooms occupied for current year P2 population proportion of rooms occupied for previous year - P2 less than or equal to 0 greater than 0 Ho P1 Ha P1 P2 b. What is the estimated proportion of hotel rooms occupied each year (to 2 decimals)? Current year .80 X Previous Year .77 c. Conduct a hypothesis test. What is the p-value (to 4 decimals)? Use Table 1 from Appendix B. Previous Year p-value = 0.0166 Using a 0.05 level of significance, what is your conclusion? We can conclude that there…

Binge-watching a television show might not be the best way to enjoy a television series (Horvath et al., 2017). Participants in an experiment were in a group that either watched an entire t.v. series during daily one-hour sessions or watched all the episodes during a single binge session. Participants were asked to rate their enjoyment of the t.v. series on a scale of 0-100. Data like those observed by the author are listed below.        Binge-watched          Daily-watched                87                              84                71                              100                73                              87                86                              97                78                              92   Is there a difference in the level of enjoyment based on whether the series was binge-watched or watched on a daily basis? Use a two-tailed test at the α = 0.05 level of significance?

A researcher wants to study how daily protein supplementation in the elderly population will affect baseline liver fat. The study budget will allow the enrollment of 62 patients. Half will be randomized to a placebo group and half to the protein supplement treatment group, and the trial will be carried out over one month. It is desired to see whether the mean change in the percentage of liver fat from baseline to the end of the study differs between the two groups in the study. The researcher needs to know what power can be obtained under the sample size restrictions to identify a change in the mean percent liver fat of 10. Based on results observed in past similar studies, a common standard deviation of 12 will be used for each treatment group in the power analysis. Assume that the significance level is 0.05.

According to the World Health Organization, obesity has reached epidemic proportions globally. While obesity has generally been linked with chronic disease and disability, researchers argue that it may also affect wages. In other words, the body mass index (BMI) of an employee is a predictor for salary. (A person is considered overweight if his/her BMI is at least 25 and obese if BMI exceeds 30.) The accompanying data file includes salary (in $1,000s) for 30 college-educated men with their respective BMI and a dummy variable that represents 1 for a white man and 0 otherwise. Salary BMI White 34 33 1 43 26 1 44 26 1 34 35 0 34 36 1 53 20 1 42 20 0 37 26 1 35 28 1 46 22 1 46 20 1 34 35 0 45 26 1 33 34 0 25 29 0 32 30 1 46 18 0 31 31 0 54 19 1 37 23 0 42 27 1 38 30 1 45 18 0 38 26 0 41 28 1 39 28 1 50 20 1 41 26 1 38 28 1 45 21 1 1. Estimate a model for Salary with BMI and White as the predictor variables. Note: Negative…

The relative risk of developing lung cancer among individuals who smoke is 15.0. Which of the following is the most accurate interpretation of this information?     Individuals who have lung cancer are 15.0% more likely to smoke than individuals who do not have lung cancer.     Individuals who have lung cancer are 15.0 times more likely to smoke than individuals who do not have lung cancer.     Individuals who smoke are 15.0 times more likely to develop lung cancer than individuals who do not smoke.     Individuals who smoke are 15.0% more likely to develop lung cancer than individuals who do not smoke.

Has the Percentage of U.S. Adults Who Smoke Decreased since 2007? With data from the 2005-2007 National Health Interview Survey, the Centers for Disease Control and Prevention estimated that about 20% of U.S. adults (18 and older) smoke. Is the percentage lower this year? Suppose we select a random sample of 100 adults (18 and older) this year. The conditions are met for use of a normal model, because we expect 20 smokers (20% of 100) in the sample and 80 nonsmokers. Both expected counts are greater than 10, so we use a z-score and a standard normal curve to assess the evidence. (The standard error is 0.04.) Suppose that 15 in our sample of 100 are smokers. Which conclusion is supported by the data? We cannot conclude that the percentage of U.S. adults (18 and older) who smoke is less than 20% this year. We can conclude that the percentage of U.S. adults (18 and older) who smoke is less than 20% this year. Incorrect. You are right that the percentage in the sample is 15% and this is…