The return rate and probability distribution of Zhongyuan Company and Southern Company are shown in Table 1.

Table 1                         The rate of return of Zhongyuan Company and Nanfang Company and its probability distribution ρ

(1)The expected return rate, standard deviation and coefficient of variation of Zhongyuan Company and Southern Company were calculated respectively.

(2)According to the above calculation results, try to judge whether investors should invest in the stock of Zhongyuan Company or the stock of Southern Company.