For problems using Stata, please cut-and-paste code and results from the output window into a word processing program and format using Courier font (or other monospace font) . Please separately state the answer to the question that you obtain from the output. Simply including the Stata output is not acceptable and will result in deduction of points.

Unless otherwise stated, all hypothesis tests should be two-sided and conducted at the 0.05 level.

This homework uses the dataset CARDIAC that you have used in many previous assignments (Homeworks #3, #5, and #6). The data and accompanying documentation file are available on Carmen. For these problems you must use Stata for calculations.

1. (20 pts) Before analyzing the data, you should summarize the sample. Do this by completing the paragraph below, filling in the blanks with the indicated summary statistics. You will need to use Stata commands such as tabulate and summarize (or tabstat). You will also need to refer to the documentation to determine the codes for the categorical variable(s).
   The sample consisted of _____subjects, of which ____% were female. The average age in the sample was __SD = _____). The mean baseline ejection fraction was _____ mmHg (SD = _____), with a range from ___ to_____. The average systolic blood pressure was_____ (SD = __
2. (6 pts) We would like to examine the relationship between baseline ejection fractionand systolic blood pressure (SBP). Create a scatterplot of these two variables (with SBPon the X-axis) and describe the trend (if any) that you see.
3. (6 pts) Use SBPas the predictor in a regression analysis to predict baseline ejection fraction. Provide the complete Stata output and separately write the estimated regression equation.
4. (10 pts) What is the estimated intercept? Carefully interpret this quantity. Does this make sense scientifically? Why or why not? Note that the units for SBP are mmHg and the units for baseline ejection fraction are % (percentage points).
5. (10 pts) What is the estimated slope? Carefully interpret this quantity.Note that the units for SBP are mmHg and the units for baseline ejection fraction are % (percentage points).
6. (8 pts) Perform a hypothesis test to determine whether SBPis significantly associated with baseline ejection fraction. Specifically, state the (1) hypotheses, (2) test statistic value, (3) p-value or critical value, (4) conclusion (in the context of the problem).
7. (6 pts) Based only on the output from your regression, calculate the estimated correlation between baseline ejection fraction and SBP.
8. (4 pts) Use Stata to confirm your calculation in question (7). Include the Stata output and highlight or otherwise identify the correlation on the output (you do not need to separately state the correlation).
9. (4 pts) Calculate the predicted baseline ejection fraction for a person whose SBP is 140 mmHg.
10. (8 pts) What is the difference in estimated mean baseline ejection fraction between a person whose SBP is 140 and someone whose SBP is 200? (Also indicate which is higher.)
11. (6 pts) In addition to SBP, we are interested in the association between age and baseline ejection fraction. Create a scatterplot of these two variables (with age on the X-axis) and describe the trend (if any) that you see.
12. (6 pts) Perform a regression analysis using age to predict baseline ejection fraction.Provide the Stata output and separately write the estimated regression equation.

13.(6 pts) Report the 95% confidence interval for the slope from the regression model in (12). Explain the relationship between this confidence interval and the hypothesis test for the slope, also on the Stata output. Be specific.

Price: $16.12

Solution: The downloadable solution consists of 6 pages, 1012 words and 2 charts.
Deliverable: Word Document