Question

The daily exchange rates for the​ five-year period 2003 to 2008 between currency A and currency B are well modeled by a normal distribution with mean 1.975 in currency A​ (to currency​ B) and standard deviation 0.034 in currency A. Given this​ model and using the​ 68-95-99.7 rule to approximate the probabilities rather than using technology to find the values more​ precisely, complete parts​ (a) through​ (d).

a) What is the probability that on a randomly selected day during this​ period, a unit of currency B was worth more than 1.975 units of currency​ A?

b) What is the probability that on a randomly selected day during this​ period, a unit of currency B was worth more than 2.009 units of currency​ A?

c)What is the probability that on a randomly selected day during this​ period, a unit of currency B was worth less than 1.907 units of currency​ A?

d)Which would be more unusual, a day of which a unit currency B was worth less than 1.709 units of currency A or more than 1.834 units of currency A?

Answer 1