Measures of Variability - Page 4
Questions
- What is the variance of z=2x+3y, in terms of the variances of x and y?
- If X and Y are correlated random variables, what is Var(XY)?
- What is the variance of the following numbers?: {40; 56; 59; 60; 60; 62; 65; 69; 75; 84}
- What is the variance of the following probability distribution?: p(0)=0.05, p(2)= 0.17, p(4)= 0.43, p(6)= 0.35?
- What is the variance of the following numbers?: {2,9,3,2,7,7,12}
- What is the variance of the following numbers?: {3,5,2,2,4,7,8,5,7,12,6,4,}
- What is the variance of the following numbers?: {8,0,9,5,3,4,5,3,7,-5,3,6,8,4,3,}
- What is the variance of {3,6,7,8,9}?
- What is the standard deviation of {1, 2, 3, 4, 5, 6, 7}?
- How do you use a probability mass function to calculate the mean and variance of a discrete distribution?
- Suppose that X is a continuous random variable whose probability density function is given by: #f(x)= k(2x - x^2) for 0 < x < 2#; 0 for all other x. What is the value of k, P(X>1), E(X) and Var(X)?
- What is the variance of the following set of numbers?: {12, 19,19, 19, 20, 20, 21, 21, 21, 22, 22, 22, 22, 22, 22,23, 23, 23, 24, 25, 26, 26, 27, 27, 28, 32}
- John received a score of 75 on a math test where the mean was 50. If his score is 2.5 standard deviations away from the mean, what is the variance of the classes test scores?
- What is the mean and variance of a random variable with the following probability density function?: #f(x) = 3x^2 if -1 < x < 1#; 0 otherwise
- What is the variance of the following numbers?: {49, 49, 52, 53, 58, 62, 68, 75}
- What is the variance of {1000, 600, 800, 1000}?
- What is the variance of {15, 14, 13, 13, 12, 10, 7}?
- If the following is a probability distribution function: #f(x)=k(e^(-x^2)+e^-x)#, what is #k# and what is the variance?
- If the following is a probability distribution function: #f(x)=k(1/x^2)#, what is k and what is the variance?
- If the median of a distribution is 1900, the mean is 2144.58, and the sample standard deviation is 884.07, what is the sample variance?