Linear combinations of random variables
6.2What the syllabus asks of you
- use, when solving problems, the results that – E(aX + b) = aE(X) + b and Var(aX + b) = a² Var(X) – E(aX + bY) = aE(X) + bE(Y) – Var(aX + bY) = a² Var(X) + b² Var(Y) for independent X and Y – if X has a normal distribution then so does aX + b – if X and Y have independent normal distributions then aX + bY has a normal distribution – if X and Y have independent Poisson distributions then X + Y has a Poisson distribution.
Read the notes first
Chapter 29: Linear combinations of random variables
Drill this topic
All 82 questions on Linear combinations of random variables, untimed — answer on paper, then mark yourself against the mark scheme.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
82 questions
These are structured questions, answered in working rather than by picking an option, so they are not listed here one by one. The drill above puts each in front of you with its mark scheme to check against.