A medical center is concerned about the length of stay, measured in days, of its patients who
Question:
A medical center is concerned about the length of stay, measured in days, of its patients who undergo joint-replacement procedures.
To this end, it has asked you to compare the length of stay of patients who received a ceramic implant (coded as 1 in the predictor variable Ceramic) to the length of stay of patients who received a conventional implant (coded as 0 in the predictor variable Ceramic).
After drawing a small random sample of the patients who received a joint replacement at this medical center, you ran the following regression model:
Length of Stay | Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% |
Intercept | 4.34 | 0.25 | 17.35 | 0.00 | 3.85 | 4.83 |
Ceramic | -0.81 | 0.26 | -3.07 | 0.00 | -1.33 | -0.29 |
1.Was there a difference in predicted length of stay between the two groups in the small random sample of the patients who received a joint replacement at this medical center?
That is, was the estimated coefficient of Ceramic different from zero numerically?
Explain your answer.
2. At a 5% level of statistical significance, do you infer that there was a difference in length of stay between the two groups in the population of all patients who received a joint replacement at this medical center?
That is, was the estimated coefficient of Ceramic different from zero statistically?
Explain your answer.
3. Compute the predicted length of stay if 60% of patients receive a ceramic implant.
4. Compute the change in predicted length of stay when the percentage of patients receiving a ceramic implant increases from 60% to 100%.
Fundamentals of Cost Accounting
ISBN: 978-0077398194
3rd Edition
Authors: William Lanen, Shannon Anderson, Michael Maher