Final answer:
The variance of the stock returns given by the student is calculated to be 104.78215% squared, following the procedure of finding the mean, calculating the deviations, squaring the deviations, and averaging them.
Step-by-step explanation:
The student is asking how to calculate the variance of stock returns based on the returns from the past four years. To compute the variance, follow these steps:
- Calculate the mean (average) of the returns.
- Subtract the mean from each of the individual returns to find the deviation of each return from the mean.
- Square each of these deviations.
- Compute the average of these squared deviations; this is the variance of the returns.
Here is how to apply these steps:
- The mean is (18.28 + (-5.40) + 20.63 + 8.77) / 4 = 10.57%.
- The deviations are 18.28 - 10.57 = 7.71%, -5.40 - 10.57 = -15.97%, 20.63 - 10.57 = 10.06%, and 8.77 - 10.57 = -1.80%.
- Square the deviations to get 59.4841, 255.2009, 101.2036, and 3.24 respectively.
- The variance is (59.4841 + 255.2009 + 101.2036 + 3.24) / 4 = 104.78215% squared.
The variance of the stock returns is 104.78215% squared.