问题：An exchange rate has a given expected future value and standard deviation.
Assuming that the exchange rate is normally distributed, what are the probabilities that the exchange rate will be at least 2 or 3 standard deviations away from its mean?
答案：The probabilities can be taken from a normal table, in which the critical z-values are 2.00 or 3.00 and we are including the probabilities in both tails. The probabilities that the exchange rate will be at least 2 or 3 standard deviations away from the mean are P ( | X − μ | ≥ 2 σ ) = 0.0456 P ( | X − μ | ≥ 3 σ ) = 0.0026
不知道答案有没有省去一些步骤。。看不懂。。
Assuming that the exchange rate is normally distributed, what are the probabilities that the exchange rate will be at least 2 or 3 standard deviations away from its mean?
答案：The probabilities can be taken from a normal table, in which the critical z-values are 2.00 or 3.00 and we are including the probabilities in both tails. The probabilities that the exchange rate will be at least 2 or 3 standard deviations away from the mean are P ( | X − μ | ≥ 2 σ ) = 0.0456 P ( | X − μ | ≥ 3 σ ) = 0.0026
不知道答案有没有省去一些步骤。。看不懂。。
他是爸
