Easy -1.2 This is a direct application of a standard variance formula Var(aX+b) = a²Var(X), requiring only one step: 4² × 5 = 80. It's a routine recall question with no problem-solving element, though slightly above trivial since it's from Further Maths and students must remember the constant term doesn't affect variance.
1 The discrete random variable $X$ has $\operatorname { Var } ( X ) = 5$\\
Find $\operatorname { Var } ( 4 X - 3 )$
Circle your answer.\\
17207780
\hfill \mbox{\textit{AQA Further Paper 3 Statistics 2019 Q1 [1]}}