solve for parts.......

Suppose that the duration of a particular type of criminal trial is known to have a mean of 15 days and a standard deviation of 5 days. We randomly sample 9 trials. Part (a) In words, define the random variable EX. O the total number of hours for the nine trials O the total number of days for the nine trials the total number of all trials O the total number of each type of trial Part (b) Give the distribution of EX. EX - Part (c) Find the probability that the total length of the 9 trials is at least 165 days. (Round your answer to four decimal places.) Part (d) Ninety percent of the total of 9 of these types of trials will last at least how long? (Round your answer to two decimal places.) days Submit