What is the lowest z-value for the highest 2% of observations on the standard normal distribution?

题目

What is the lowest z-value for the highest 2% of observations on the standard normal distribution?
a.-2.0537
b.-0.8416
c.0.8416
d.2.0537
The daily sales of a retail store are normally distributed with a standard deviation of $500.If the probability that sales will be less than $10,000 in any one day is 40%,what are the mean daily sales?
a.$9,873.35
b.$10,126.65
c.$12,533.65
d.None of the above

答案

cd.