The mean yearly rainfall in Sydney, Australia, is about 137 mm and the standard deviation is about 69 mm ("Annual maximums of," 2013).Assume rainfall is normally distributed.

a.)State the random variable.

b.)Find the probability that the yearly rainfall is less than 90 mm.

c.)Find the probability that the yearly rainfall is more than 225 mm.

d.)Find the probability that the yearly rainfall is between 140 and 240 mm.

e.)If a year has a rainfall less than 100 mm, does that mean it is an unusually dry year?Why or why not?

f.)What rainfall amount are 85% of all yearly rainfalls more than?