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A-Level MathematicsYear 2022Q2

4   2. The discrete random variable X has probability distribution x –5 –1 0 5 b P(X = x) 0.3 0.25 0.1 0.15 0.2 where b is a constant and b > 5 (a) Find E(X ) in terms of b (1) Given that Var(X ) = 34.26 (b) find the value of b (4) (c) Find P(X 2 < 2 – 3X ) (4) ___________________________________________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Turn over 5   Question 2 continued _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___________________________________________ (Total for Question 2 is 9 marks)

Paper Source:9fm0-3b-que-20220618.pdf

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Exam Specification Info

This question is part of the UK A-Level Mathematics syllabus. In the actual exam, structured questions typically require linking specific keywords to gain full marks. Applaa helps you drill these topics.

Syllabus levelAdvanced Level (A-Level)

SubjectMathematics

Official MarksVariable (2–6 marks)