NO.PZ2018062016000048
问题如下:
Peter bought a security for $55 in year 1, $60 in year 2, $64 in year 3, $70 in year 4. The harmonic mean of the price will be:
选项:
A.
61.77.
B.
25.
C.
37.04
解释:
A is correct. The harmonic mean : 4/[(1/55) + (1/60) + (1/64) + (1/70)] = 61.77
这个题,我用考试计算器算出来的是61.83,请问是为什么?小数点设的是6位,误差会有这么大吗……