| Exam Board | Edexcel |
|---|---|
| Module | S4 (Statistics 4) |
| Marks | 2 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | F-test and chi-squared for variance |
| Type | Find critical region for F-test |
| Difficulty | Standard +0.3 This is a straightforward F-distribution table lookup question requiring students to find a lower critical value given the upper critical value and total probability. It involves basic understanding of F-distribution symmetry properties and table reading, with minimal calculation or conceptual depth—slightly easier than average for A-level. |
| Spec | 5.04a Linear combinations: E(aX+bY), Var(aX+bY) |
Find the value of the constant $a$ such that
$$\text{P}(a < F_{8,10} < 3.07) = 0.94$$
[2]
\hfill \mbox{\textit{Edexcel S4 Q1 [2]}}