Solution — 2016 Question 6 Sampling

(a)

Out of syllabus.

(b)

Out of syllabus

(c)

\begin{matrix} \overline{x} & = \frac{312}{80} \\ = 3.9 ∎ \end{matrix}

\begin{matrix} s^{2} & = \frac{1328 - \frac{97 344}{80}}{79} \\ = \frac{556}{395} \\ = 1.41 ∎ (to 3 s.f.) \end{matrix}