Imagine you are a statistical consultant and your client, a weightlifting supplement company, is looking to see if their product is effective in increasing muscle mass gained over a training cycle. You randomly sampled 20 female weightlifters and assigned them to take the supplement and 20 to take a placebo. You have both groups run the same controlled training program over 12 weeks and calculated their whole body lean mass difference in pounds from the beginning to the end of the program. Can you infer that the supplement group gained more muscle mass on average than the placebo group? Use a = 0.05 for any hypothesis test. 1) State the research question in one sentence and use the question to determine the parameter we are using to conduct statistical inference. Describe this parameter in one sentence using symbols and a description.

Help me please

Ride services are on the rise, such as Uber and Lyft. You wondered if the recent news reports of crime occurring with these ride services impacted the usage of them, especially with women. You decide to conduct  a survey about ride service usage among male and female college students. The results showed that 19 males use ride services and 11 do not. While 12 females use ride services and 18 do not. Calculate the chi-square statistic:

PETROGAS is testing new filters for its motorbikes. One brand of filter (Filter A) is placed in one motorbike, and the other brand (Filter B) is placed in the second motorbike. Random samples of air released from the motorbikes are taken at different times throughout the day. Pollutant concentrations are measured for both motorbikes at the same time. The following data attached represent the pollutant concentrations (in parts per million) for samples taken at 20 different times after passing through the filters. a. Test the hypothesis that the mean for the pollutant concentration for Filter B is greater than 30. Use the 1% level of significance. b. Construct a 95% confidence interval for the difference in mean pollutant concentration, where a difference is equal to the pollutant concentration passing through Filter A minus the passing through Filter B. c. Using the 5% significance level, determine whether there is evidence that mean for the pollutant concentration for Filter A…

A personal trainer wanted to test the effectiveness of two different workout routines. She took a random sample of 70 of her clients and, in a random order, had them complete one of the two routines for two weeks. Then, after a one-month waiting period, she asked them to come back and do the other routine for two weeks. After each two-week period of the exercise routines, she measured their performance on a physical fitness aptitude test. She found the average difference in aptitude scores between the two routines for each client was 30.4 with a standard error of 3.2. What would be her 85% confidence interval for the average difference in the effectiveness of the two routines? (3 decimal places) (  ,  )

A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions.     CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600       CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400   1. Compute the appropriate measure of association for those who were less than age 50.  2. Compute the appropriate measure of association for those who were older or equal to age 50.  3. Compute the crude measure of association?  4. List three attributes that age must satisfy before it could…

The Wall Street Journal asked Concur Technologies, Inc., an expense management company, to examine data from 8.3 million expense reports to provide insights regarding business travel expenses. Their analysis of the data showed that New York was the most expensive city. The following table shows the average daily hotel room rate (X) and the average amount spent on entertainment (Y) for a random sample of 9 of the 25 most-visited U.S. cities. These data lead to the estimated regression equation y = 17.49 + 1.0334x. For these data SSE = 1541.4. Use Table 1 of Appendix B.  a. Predict the amount spent on entertainment for a particular city that has a daily room rate of $89 (to 2 decimals). b. Develop a 95% confidence interval for the mean amount spent on entertainment for all cities that have a daily room rate of $89 (to 2 decimals). c. The average room rate in Chicago is $128. Develop a 95% prediction interval for the amount spent on entertainment in Chicago (to 2 decimals).