The standard deviation of return on investment A is 0.10, while the standard deviation of return on investment B is 0.04. The variance is a way of measuring the typical squared distance from the mean and isn’t in the same units as the original data. It is the square root of signal variance which is exactly the same as the average ... Look up probability density function. Standard deviation and variance are both determined by using the mean of a group of numbers in question. The standard deviation of a random variable is the square root of the variance. 5.3 Variance and standard deviation. What type of risk is measured by the standard deviation?Answer: The standard deviation is a measure of a security's (or a portfolio's) stand-alone risk. View solution Suppose values taken by a variable X are such that a ≤ x i ≤ b where x i denotes the value of X in the i i h case for i = 1 , 2 , . Example 1 Find the variance and standard deviation for the heights of the Dolphins (treating them as a population). The variance is therefore 2. With the help of the variance and standard deviation formula given above, we can observe that variance is equal to the square of the standard deviation. (for interest, the variance would be measured in potatoes2) Find the mean and the standard deviation of the combined set of 25 numbers. ... Let X be a continuous random variable with PDF g(x) = 10 3 x 10 3 x4; 0