Home › CBSE Class 11 (Commerce) › Mathematics › Statistics › If y = 2x + 3 and x has variance 9, what is the …
If y = 2x + 3 and x has variance 9, what is the variance of y?
A39
B21
C81
D36
Answer & Solution
Correct answer: D. 36
Adding 3 leaves variance unchanged, while multiplying by 2 multiplies it by 4, giving 36.
Related questions
A set has 8 equal observations. Its variance and range areVariance is the mean of squared deviations, whereas standard deviation isPopulation standard deviation of 2, 4, 4, 4, 5, 5, 7, 9 isWhy is range only a rough measure of dispersion?With Q1 = 20 and Q3 = 45, the quartile deviation (half the IQR) isFor the interquartile range, if Q1 = 20 and Q3 = 45, the IQR isWhy is the plain sum of squared deviations a poor dispersion measure for sets of unequal sThe sum of squared deviations of 5, 15, 25, 35, 45, 55 from their mean 30 is 1750. The var