Suppose that the random variable X has a mean u = 5 and standard deviation o=8. The mean and standard deviation of Y=2X-4 is?

The answer is 6 and 16, respectfully, and I do not know how to get there. Anybody willing to help me out?

- Thread starter iain08
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Suppose that the random variable X has a mean u = 5 and standard deviation o=8. The mean and standard deviation of Y=2X-4 is?

The answer is 6 and 16, respectfully, and I do not know how to get there. Anybody willing to help me out?

Suppose that the random variable X has a mean u = 5 and standard deviation o=8. The mean and standard deviation of Y=2X-4 is?

The answer is 6 and 16, respectfully, and I do not know how to get there. Anybody willing to help me out?

Your professor should have covered the properties of the Expectation Operator i.e. E[X]. If you understood these properties, then the answers to your question should be straight-forward to you.

Well we did that, but the data was given by a chart that had both X and Y and their probabilities at each number and we found out everthing from there. So normally I would take the Covariance of X and Y and subtract the product of the two means from that.

Start with just the mean.