| Exam Board | Edexcel |
|---|---|
| Module | S4 (Statistics 4) |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Topic | F-test and chi-squared for variance |
| Type | F-test two variances hypothesis |
| Difficulty | Standard +0.3 This is a straightforward lookup question requiring students to use F-distribution tables with given degrees of freedom. It involves finding two probabilities and subtracting them, which is routine for S4 students familiar with F-tables, though the reciprocal transformation requires understanding the symmetry property F(v1,v2) = 1/F(v2,v1). Slightly easier than average due to being purely procedural with no conceptual challenge. |
| Spec | 5.04a Linear combinations: E(aX+bY), Var(aX+bY) |
The random variable $X$ has an $F$-distribution with 8 and 12 degrees of freedom.
Find P$\left(\frac{1}{5.67} < X < 2.85\right)$. [4]
\hfill \mbox{\textit{Edexcel S4 Q1 [4]}}