Mean And Standard Deviation For Sums And Differences Of Independent Random Variables

Question 0

In general, the mean of a set of differences is equal to….

Answer 0

The difference of the means of the two original sets

Question 1

We say two variables X and Y are independent if….

Answer 1

P(x|y)= P(x) for all values of x and y

P(x n y)= P(x)P(y)

Question 2

If a sum is formd by picking one element from each of several sets, the mean of such sums is….

Answer 2

Simply the sum of the means of the various sets

Question 3

If a total is formed by a procedure that adds or subtracts one element from each of several independent sets, the variance of the resulting totals is…..

Answer 3

Simply the same of the variances of the serval sets

Pg. 255

Question 4

If two random variables are independent, the variance of the sum (or difference) of the two random variables is equal to…

Answer 4

The sums of the two individual variances

Question 5

Variances and range are both measures of…

Answer 5

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