Answer:
A) X = 9.2%, Y = 11.8%
B) VARX = 204.2, VARY = 527.7
C) SD.X = 14.29, SD.Y = 22.97
Explanation:
Given that;
Returns
year X Y
1 15% 21%
2 26 26
3 7 13
4 -13 -26
5 11 15
a) arithmetic average returns (mean)
Mean = ∑x / n
Mean X = [15 + 26 + 7 - 13 + 11] / 5 = 46 / 5 = 9.2%
MeanY = [21 + 36 + 13 - 26 + 15] / 5 = 59 / 5 = 11.8 %
b) the variances
VAR = ∑(x-mean)² / n-1
VARX = [(15 - 9.2)² + (26 - 9.2)² + (7 - 9.2)³ + (-13 - 9.2)² + (11 - 9.2)²] / (5 - 1)
= [33.64 + 282.24 + 4.84 + 492.84 + 3.24] / 4 = 816.8 / 4 = 204.2
VARY = [(21 - 11.8)² + (36 - 11.8)² + (13 - 11.8)² + (-26 - 11.8)² + (15 - 11.8)²] / (5 - 1)
= [84.64 + 585.64 + 1.44 + 1,428.84 + 10.24] / 4 = 2,110.8 / 4 = 527.7
c) the standard deviations
SD = √ Variance
SD.X = √204.2 = 14.29%
SD.Y = √527.7 = 22.97%