3. (30 points total) Consider the following study involving four battery brands (A, B, C, and D), operating conditions (room temperature or cold) and the time for the battery to fail once a load is placed on it. The data is in the text file BatteryFail.txt. You may copy and paste the contents of BatteryFai1.txt into data lines in a SAS data step you create. There should be three variables: one indicating the time to failure, one for the temperature condition, and one for the brand. a. (15 points) Use PROC MEANS to display the mean and median of time to failure for each of the four brands. Compare the four brands based on mean and median. Write your answer as a comment in your SAS program. b. (15 points) Use PROC MEANS to display the mean and median of time to failure for the two operating conditions. Compare the operating conditions based on mean and median. Write your answer as a comment in your SAS program