Edexcel S1 2002 January — Question 3

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2002
SessionJanuary
TopicDiscrete Probability Distributions
TypeTwo unknowns from sum and expectation
3. A discrete random variable \(X\) has the probability function shown in the table below.
\(x\)012
\(\mathrm { P } ( X = x )\)\(\frac { 1 } { 3 }\)\(a\)\(\frac { 2 } { 3 } - a\)
  1. Given that \(\mathrm { E } ( X ) = \frac { 5 } { 6 }\), find \(a\).
  2. Find the exact value of Var ( \(X\) ).
  3. Find the exact value of \(\mathrm { P } ( X \leq 15 )\).
This paper (6 questions)
View full paper
Q1 Q3 Q4 Q5 Q6 Q7