To find the power of the given conditions, I found the SE and the z-value at the significance level of 0.05. However, I am stuck on how to find the rejection level. How do I find the power when there are no extra information given?

Thankyou!

Use the following for questions 19, 20, and 21. A drug manufacturer is developing a new drug meant to shorten the duration of the common cold, and is preparing a clinical trial to test the drug's effectiveness. To accommodate the possibility of potential adverse effects, they consider the two-sided hypothesis Ho : Atreatment - Acontrol = 0 HA : /treatment - /control # 0 at the o = 0.05 level of significance, where /treatment and /control are the average duration of the colds for the treatment and control groups, respectively, measured in days. Patients participating in the trial are randomly assigned to each group, and are monitored closely around-the-clock after the onset of their cold symptoms until they have subsided. Based on historical data, they assume that the standard deviation for cold durations is o = 3.5 days in both groups. The manufacturer is interested in detecting a shortening of cold duration by at least 1.5 days. If they recruit 30 patients for each group, what is the probability they'll be able to detect a 1.5 day reduction in cold symptom duration? (i.e. find the power for this effect size and sample size.) Use a = 0.05. Give your answer to at least two decimal places. Page 5