130 problems in this skill, each with a solver-verified answer key. Answers are checked the moment you submit — with a hint if you want one and a worked solution afterwards.
What the problems look like
A few statements from this skill. Answers, hints and worked solutions live in the practice session.
Warm-up
Suppose Cov(X,Y)=−2. Let U=aX+b and V=cY+d, where a=1, b=4, c=3 and d=5. Using the property Cov(aX+b,cY+d)=acCov(X,Y), compute Cov(U,V).
Warm-up
Suppose Cov(X,Y)=−5. Let U=aX+b and V=cY+d, where a=3, b=1, c=−2 and d=−2. Using the property Cov(aX+b,cY+d)=acCov(X,Y), compute Cov(U,V).
Warm-up
Suppose Cov(X,Y)=10. Let U=aX+b and V=cY+d, where a=−4, b=5, c=−3 and d=−3. Using the property Cov(aX+b,cY+d)=acCov(X,Y), compute Cov(U,V).
Problems shown under their original terms: Generated (template, solver-computed).
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