Let x be a random variable with mean x = 25 and x = 6 and let y be a random variable with mean y = 30 and y = 4. it is known that x and y are independent random variables. suppose the random variables x and y are added together to create new random variable w (i. e., w = x + y). what is the standard deviation of w?

I'm guessing you intended to say has mean and standard deviation , and has means and standard deviation .

If , then has mean

and variance

Given that and , we have

Then

and are independent, so , and

so that the variance, and hence standard deviation, are

# # #

Alternatively, if you've already learned about the variance of linear combinations of random variables, that is

then the variance of is simply the sum of the variances of and , , and so the standard deviation is again .

no, the equation would be invalid since they are both not equal.

step-by-step explanation:

here you got

4y-6+4y 2-9

first, you would simplify the equation on the form.

4y-6+4y 2-9

then, move all the terms that contains a y to the left and all the other terms to the right.

+4y-4y+-9-6

finally, you will simplify the left and the right side of the equation.

y=-3

40% off the regular price is the correct answer.

step-by-step explanation: