[2 marks] Typically, elderly patients with hip fractures can spend a long time in recovery. A new physiotherapy program is developed and researchers want to see if this new program gives improved recovery times from the typical average amount. A random sample of 10 patients was enrolled in the new program and the amount of time each patient spent in hospital {measured in days) is recorded below. 12719131722111415 Using this data as a pilot study. determine the sample size needed to estimate the true mean recovery time with this new physiotherapy program to within I115 days with 90% confidence