The latest antidepressant produced is currently involved in the testing process. Eight subjects have joined the testing process where the mean number of days taken before side effects disappeared is being examined. The results are as follows. 9, 16, 7, 27, 25, 19, 21, 15 USE SALT (a) How many degrees of freedom are present in this study? (b) What is the point estimate (in days)? days What is the standard deviation (in days) of the sample? (Round your answer to four decimal places.) days (c) What is the 95% confidence interval (in days) for the population mean? (Use a table or technology. Round your answers to three decimal places.) days (d) Interpret the 95% confidence interval for the population mean. We are 95% confident all results are in this interval. We know that 95% of the results will be in the interval. Ninety-five percent of the data are outside of the interval. We are 95% confident that the true mean is contained in the interval.