The director of admissions at Long Beach Hospital believes that patient residence time (i.e., the length of stay in the hospital) has been dropping over the last several years. Two years ago the average residence time was four days. The director examines the records of 40 recently released patients and finds that the average residence time was 3.5 days with a standard deviation of 1.2 days. What conclusions regarding patient residence time can be drawn from the survey results at a 90% level of confidence? As part of your assessment, include a statement of the null and alternate hypothesis, decision criteria, test statistic, decision, and the p -value.

*Conduct left-tail test