| Exam Board | Edexcel |
| Module | FS2 (Further Statistics 2) |
| Year | 2019 |
| Session | June |
| Topic | Hypothesis test of a normal distribution |
6 A company manufactures bolts. The diameter of the bolts follows a normal distribution with a mean diameter of 5 mm .
Stan believes that the mean diameter of the bolts is less than 5 mm . He takes a random sample of 10 bolts and measures their diameters. He calculates some statistics but spills ink on his work before completing them. The only information he has left is as follows
\includegraphics[max width=\textwidth, alt={}, center]{67df73d4-6ce4-45f7-8a69-aa94292ea814-16_394_1150_527_456}
Stating your hypotheses clearly, test, at the \(5 \%\) level of significance, whether or not Stan's belief is supported.