3.
a. A researcher wants to study how long (in days) patients aged30-39 who are admitted to a hospital for coronavirus treatmentspend in the hospital before being discharged. Preliminary datasuggests that
? = 4 days is a safe assumption. Assuming the recovery times havestandard deviation 4 days (which would say that virtually allpatients recover in some number of days +/- about 12 days), use theformula
? = ?^2 * ?^2 / ?^2
To find the number of patients that would need to be sampled toconstruct a 95% confidence interval for the mean recovery time witha margin of error of 0.5 days. Make sure to show how you find thecritical value z
b. Same question as part a, if instead you assume that ? = 3.5days.
