The daily exchange rates for the two-year period 2011 to 2013 between the Japanese Yen (JPY) and the Australian Dollar (AUD) can be modelled by a Normal distribution with mean, = 83 Yenand a standard deviation ,= 22 Yen.

What is the probability that on a randomly selected day during this period, the dollar was worth less than55 Yen?(4 dp)

What proportion of the days during this period will the dollar be worth between55 and 87 Yen?(4 dp)

If you select a window of 150 days during this period, how many days would you expect the dollar to worth between55 and 87 Yen?(round to nearest integer)