NO.PZ2021061603000023
问题如下：
A portfolio manager invests €5,000 annually in a security for four years at the prices shown in the following exhibit.
The average price is best represented as the:
选项：
A. harmonic mean of €76.48
B. geometric mean of €77.26
C. arithmetic average of €78.00
解释：
A is correct. The harmonic mean is appropriate for determining the average price per unit. It is calculated by summing the reciprocals of the prices, then averaging that sum by dividing by the number of prices, then taking the reciprocal of the average:
4/[(1/62.00) + (1/76.00) + (1/84.00) + (1/90.00)] = €76.48
我不太懂答案b为什么不对呢
