A team of aerospace engineers is testing two types of wind-speed sensors, Sensor X and Sensor Y, on 8 experimental drone flights. The readings (in knots) are recorded below:
| Flight | A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|---|
| Sensor X | 12 | 15 | 8 | 22 | 19 | 5 | 25 | 10 |
| Sensor Y | 14 | 18 | 6 | 20 | 24 | 7 | 23 | 9 |
Calculate Spearman's rank correlation coefficient for these readings.
Test, at the 5% level of significance, whether there is a positive correlation between the sensors' readings. State your hypotheses clearly.
Sensor Y's reading for Flight F was later corrected to 6 knots. Explain how you would calculate Spearman's rank correlation coefficient in this case, without performing any new calculations.
316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.