The Correlation Between X and Y A $X$ And $Y$ By the Product of the Two Standard Deviations

question 6

Short Answer

The correlation between X and Y a. cannot be negative since variances are always positive.
b. is the covariance squared.
c. can be calculated by dividing the covariance between $X$ and $Y$ by the product of the two standard deviations.
d. is given by $\operatorname { corr } ( X , Y ) = \frac { \operatorname { cov } ( X , Y ) } { \operatorname { var } ( X ) \operatorname { var } ( Y ) }$ .

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Definitions:

X

Often used to represent an unknown value in algebraic expressions and equations.

Inches

A unit of length in the imperial and US customary systems, equivalent to 1/12 of a foot.

Perimeter

The total distance around the edge of a two-dimensional shape, calculated by adding together the lengths of all the sides.

Length

The measurement of something from end to end or along its longest side.