ll'ilLIEETllrlll 3 a} b} The waiting time at an elevator in a shopping mall is approximately normally distributed with a mean of 3.2 minutes and a standard deviation of 1.5 minutes. i} What is the probability ifthe waiting time is at most 2.3 minutes? {2 marks} iii) Find the probability that the waiting time is more than 3 minutes. (3 marks) ii} Find the value of k if 95% of all the customers are having waiting time of less than k minutes. (3 marks) An important factor in solid missile fuel is the particle size distribution. Based on the production data in the past, it has been determined that the particle size [in micrometers] distribution, I is having the following probability density function. _ 1232(13} :[lExEl \"30! l] ;othcrs i} State the type of the random variable X and calculate the expected value of x. (4 marks) ii} Find PU: at p}. {4 marks)