| Exam Board | Edexcel |
|---|---|
| Module | S3 (Statistics 3) |
| Session | Specimen |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Z-tests (known variance) |
| Type | One-tail z-test (upper tail) |
| Difficulty | Moderate -0.3 This is a straightforward one-sample z-test application with all values clearly stated. Students must identify hypotheses (H₀: μ=80, H₁: μ>80), calculate z = (83-80)/(15/√100) = 2.0, and compare to critical value 1.645. The setup is standard textbook material with no conceptual subtleties, making it slightly easier than average, though it does require proper hypothesis test structure. |
| Spec | 5.05c Hypothesis test: normal distribution for population mean |
\begin{enumerate}
\item A report states that employees spend, on average, 80 minutes every working day on personal use of the Internet. A company takes a random sample of 100 employees and finds their mean personal Internet use is 83 minutes with a standard deviation of 15 minutes. The company's managing director claims that his employees spend more time on average on personal use of the Internet than the report states.
\end{enumerate}
Test, at the $5 \%$ level of significance, the managing director's claim. State your hypotheses clearly.\\
\hfill \mbox{\textit{Edexcel S3 Q1 [7]}}