The annual returns (in percent)for a sample of stocks in the technology industry over the past year are as follows: 4.2 -9.4 2.8 -16.0 -6.6.
The sample standard deviation is the closest to _____.
A) 7.59
B) 8.49
C) 57.61
D) 72.01

Question

Quizplus · Accepted Answer

To find the sample standard deviation, we first need to find the sample mean, which is (-9.4 - 6.6 + 2.8 - 16 + 4.2)/5 = -2.4. Then, we can calculate the deviations from the mean for each data point: 6.6, -3.8, 5.2, -13.6, and -4.2. Squaring these deviations gives us 43.56, 14.44, 27.04, 184.96, and 17.64. The sum of these squared deviations is 288.04. To get the sample variance, we divide by n-1, which in this case is 4, to obtain 72.01. Finally, the sample standard deviation is the square root of the sample variance, which is approximately 8.49. Therefore, the closest answer choice is B.

The Annual Returns (In Percent)for a Sample of Stocks in the Technology