What’s the variance of variable X whose grouped FDT is given by 

X-values:          xi    2    4    8    3    5    6 

Frequencies:     fi    2    3    0    1    1    2 

(A) 3.5 

(B) 1.5 

(C) 2 

(D) 4 

(E) 3 

(F) 7

In a stock market during one month, the mean price of stock α was $1, 500 with standard deviation $120 and the mean price for stock β were $50 with standard deviation $10. Which of the followings is true? 

(A) Stock β has less variation. 

(B) Stock α has more variation. 

(C) Stock α is less risky. 

(D) Both stocks have same variation. 

(E) Nothing can be said about their variations.