Use expectation and variance rules - context restriction
For a transport depot decision score, \(E(X)=25\) and \(E(Y)=7\). If \(S=2X-Y\), find \(E(S)\). Enter the requested value and choose the interpretation that matches the result.
Worked practice: result and interpretation
Calculate the requested result first, then choose the interpretation that follows from it.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.