Also 1. What is the test statistic? 2. Critical value? Do you accept or reject the null hypothesis?

It is known from longstanding medical records that hospital recovery time prior to discharge for serious back surgery in Canada is normally distributed with u = 12 days and 6 = 3 days. Given this, answer the following . . ........ What is the probability of having a recovery time of more than 18 days? (to 4 decimal places) A Helath official wonder if recovery time have changed as a result of challenges associated with the recent COVID pandemic. To investigate this they examine the randomly chosen health records of 35 recent back surgery patients and find a mean recovery time of 15 days. At the .05 significance level test the following hypotheses that recovery time is different: Ho : H = 12 Hi : u # 12