If variance of x is 5, then find the variance of (2 – 3x)(a) 10(b) 45(c) 5(d) -13
Question
If variance of x is 5, then find the variance of (2 – 3x)
(a) 10
(b) 45
(c) 5
(d) -13
Solution
The variance of a random variable X is given by Var(X). If we have a new variable Y = aX + b, where a and b are constants, then the variance of Y is given by Var(Y) = a^2 * Var(X).
In this case, X has a variance of 5, and we want to find the variance of Y = 2 - 3X.
Step 1: Identify the constants a and b in the equation Y = aX + b. Here, a = -3 (the coefficient of X) and b = 2 (the constant term).
Step 2: Substitute the values of a and Var(X) into the formula Var(Y) = a^2 * Var(X).
Var(Y) = (-3)^2 * 5 = 9 * 5 = 45.
So, the variance of Y = 2 - 3X is 45. Therefore, the correct answer is (b) 45.
Similar Questions
What is the variance of a random sample of size 5 that is taken with replacement from a population with mean = 15 and variance = 10?
A data set contains the following values: 11, 3, 5, 18, 1, 4, 7. Find the population variance. Round your answer to 4 decimal places.
Consider a sample with data values of 10, 20, 12, 17, and 16. Compute the variance and standarddeviation.
Suppose X is a random variable with possible outcomes 0 and 2, with P( X = 2 ) = 0.3. The variance of X is
f x and y are related by y = 2x+ 5 and the SD and AM of x are known to be 5 and 10 respectively, thenthe coefficient of variation is(a) 25(b) 30(c) 40(d) 20
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.