问题如下:
Annual returns and summary statistics for three funds are listed in the following table:
The fund that shows the highest dispersion is:
选项:
A. Fund PQR if the measure of dispersion is the range.
B. Fund XYZ if the measure of dispersion is the variance.
C. Fund ABC if the measure of dispersion is the mean absolute deviation.
解释:
C is correct.
The mean absolute deviation (MAD) of Fund ABC’s returns is greater than the MAD of both of the other funds.
where \(\overline X\) is the arithmetic mean of the series.
MAD for Fund ABC =
MAD for Fund XYZ =
MAD for Fund PQR =
A and B are incorrect because the range and variance of the three funds are as follows:
The numbers shown for variance are understood to be in "percent squared" terms so that when taking the square root, the result is standard deviation in percentage terms. Alternatively, by expressing standard deviation and variance in decimal form, one can avoid the issue of units; in decimal form, the variances for Fund ABC, Fund XYZ, and Fund PQR are 0.0317, 0.0243, and 0.0110, respectively.
如果是看A错,B错,直接选C,是不是不保险