Correlation under rescaling

The correlation between random variables $X$ and $Y$ is $\rho(X, Y) = 0.56$ . What is the correlation $\rho(8X,\ Y + 7)$ ?

Show hints (2)+

Write correlation as covariance divided by the two standard deviations, then push the transformations through.
A positive scale multiplies both numerator and one denominator factor by the same amount; a shift changes nothing. What's left?

Answer

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0.56

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