Edexcel S2 2004 June — Question 2 5 marks

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2004
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicContinuous Uniform Random Variables
TypeState or write down basic properties
DifficultyEasy -1.3 This is a straightforward application of standard uniform distribution formulas with no problem-solving required. Students simply need to recall that P(X<a) = (a-lower)/(upper-lower), E(X) = (a+b)/2, and Var(X) = (b-a)²/12, then substitute the given values [-1, 4]. This is easier than average as it tests only direct formula recall with simple arithmetic.
Spec5.03b Solve problems: using pdf

The continuous random variable \(X\) is uniformly distributed over the interval \([-1, 4]\). Find
  1. P\((X < 2.7)\), [1]
  2. E\((X)\), [2]
  3. Var \((X)\). [2]

The continuous random variable $X$ is uniformly distributed over the interval $[-1, 4]$.

Find
\begin{enumerate}[label=(\alph*)]
\item P$(X < 2.7)$, [1]
\item E$(X)$, [2]
\item Var $(X)$. [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel S2 2004 Q2 [5]}}