9231 P21 - Jun 2017 - Q9 - 10 marks
6148
Two fish farmers \(X\) and \(Y\) produce a particular type of fish. Farmer \(X\) chooses a random sample of 8 of his fish and records the masses, \(x \mathrm{~kg}\), as follows.
\[\begin{array}{llllllll}
1.2 & 1.4 & 0.8 & 2.1 & 1.8 & 2.6 & 1.5 & 2.0
\end{array}\]
Farmer \(Y\) chooses a random sample of 10 of his fish and summarises the masses, \(y \mathrm{~kg}\), as follows.
\[\Sigma y=20.2 \quad \Sigma y^{2}=44.6\]
You should assume that both distributions are normal with equal variances. Test at the \(10 \%\) significance level whether the mean mass of fish produced by farmer \(X\) differs from the mean mass of fish produced by farmer \(Y\).
