Bear Inc.'s share price closed at $100, $105, $56, $30, $2 over five successive weeks. The weekly standard deviation of the stock price calculated from this sample is

Question

Quizplus · Accepted Answer

To calculate the weekly standard deviation , we need to first calculate the sample mean:
(100+105+56+30+2)/5= 58.6

Then we calculate the deviation of each observation from the sample mean and square it:
(100-58.6)^2 = 1708.96
(105-58.6)^2 = 2212.09
(56-58.6)^2 = 6.76
(30-58.6)^2 = 815.96
(2-58.6)^2 = 2916.36

Next, we sum up all of these squared deviations:
1708.96 + 2212.09 + 6.76 + 815.96 + 2916.36 = 9659.13

Then, we divide this sum by the number of observations minus one (since this is a sample, not the full population):
9659.13 / 4 = 2414.78

Finally, we take the square root of this result to get the standard deviation:
√(2414.78) ≈ $44.43

Bear Inc'S Share Price Closed at $100, $105, $56, $30, $2