The daily exchange rate of one dollar in euros during the first three months of 2007 can be inferred to have the following distribution.

a. Show that P (x) is a probability distribution.

b. What is the probability that the exchange rate on a given day during this period will be at least 0.75? c. What is the probability that the exchange rate on a given day during this period will be less than 0.77? d. If daily exchange rates are independent of one another, what is the probability that for two days in a row the exchange rate will be above 0.75?