原版书后题256页第8题，这个C是代表什么，看了答案也不是很明白，麻烦解释。

An analyst determines that approximately 99% of the observations of daily sales for a company are within the interval from $230,000 to $480,000 and that daily sales for the company are normally distributed. If approximately 99% of all the observations fall in the interval μ±3σ, then using the approximate z-value rather than the precise table, the standard deviation of daily sales for the company is closest to: A $83,333. B $62,500. C $41,667. 一点思路都没有

请问第六题题目问的什么意思，以及A选项的解释，非常感谢

题目里说的不是ROE低于行业的原因吗 为什么解题思路写的是ROA其中的两个Ratio

An investor invested $10,000 into an account five years ago. Today, the account value is $18,682. What is the investor's annual rate of return on a continuously compounded basis? A 12.50%. B 11.33%. C 13.31%. 什么是 a continuously compounded basis?

A stock value is three times than last year. calculate the continuously compounded return over the period: A 18.2%. B 69.3%. C 110.0%. 这个用计算器怎么按？我假设起初是1，期末是3，3-1/1=2，2，2nd，ex次方，-1，最后等于6.389

An increase in which of the following items will most likely result in a wider confidence interval for the population mean? A Reliability factor B Degrees of freedom C Sample size 可以wider confidence interval的都有哪些？

百题98答案是不是错了？

一个天数上升 一个天数下降 总体不是应该不变吗

客户分类里的mandate 是什么意思