b. Calculate the average and sum of all the elements in a1. c. Create a random vector (with 47 elements) following a normal distribution (using morm function, look up the documentation) with a mean equal to 300 and a standard deviation equal to 50. Call it a2. d. Round a2 to zero digits, i.e. make the elements integers. (Hint: use round function). e. Write a code to select elements of a2 where: i. a2 is even. ii. a2 is not divisible by three. iii. a2 is even but is not divisible by three. Question 2: What is the mean of the vec1