Do tomorrow

suppose that the duration of a particular type of criminal trial is known to have a mean of 18 days and a standard deviation of 6 days. we randomly sample 9 trials.
part(a)
in words, define the random variable ex

the total number of hours for the nine trials

the total number of all trials

the total number of days for the nine trials

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 196 days (round your answer to four decimal places)

part (d)
eighty 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