怎么计算weight mean average price?

问题如下：

An investor invests $3,000 annually in a financial product for four years at the following prices: $40.00, $55.00, $62.00, and $70.00. Which average price calculation is most suitable for this context?

选项：

A.

Weighted mean of $59.25

B.

Harmonic mean of $54.35

C.

Arithmetic mean of $61.75

解释：

Sum of reciprocals = 1 / 40.00 + 1 / 55.00 + 1 / 62.00 + 1 / 70.00 =0.025 + 0.01818 + 0.01613 + 0.01429 = 0.07360

Harmonic Mean = 4 / 0.07360 = 54.35

So, the harmonic mean of the given prices is approximately $54.35.