What is the variance of z=2x+3y, in terms of the variances of x and y? Statistics Organizing and Summarizing Data Measures of Variability 1 Answer Chandra S. Oct 19, 2015 V(z) = V(2x + 3y) = #2^2# #xx# V(x) + #3^2# #xx# V(y) = 4V(x) + 9V(y) Explanation: V[ax + by] = #a^2# V(x)+ #b^2# V(y) is the formula employed. Answer link Related questions How are the measures of central tendency and measures of dispersion complementary? Can the standard deviation be greater than the mean? Can the standard deviation ever be negative? What is the sample standard deviation formula? What is the symbol for the sample standard deviation? What are the symbols for the sample variance and for the population variance? Which data set has a larger standard deviation? First Data Set: 2, 4, 6, 8 Second Data Set:... If the standard deviation of a distribution is s = 7, what is its variance? Is the sample standard deviation "s" a resistant measure? How do you calculate the range of a data set? See all questions in Measures of Variability Impact of this question 8226 views around the world You can reuse this answer Creative Commons License