Aerospace engineers are investigating the relationship between the wing-tip vibration frequency (vvv, in Hz) and the internal cabin noise level (NNN, in dB) of a prototype long-range drone. In a series of 50 flight trials, the product moment correlation coefficient was calculated to be r=0.354r = 0.354r=0.354. Assuming the data is drawn from a population follows a bivariate normal distribution, perform a hypothesis test at the 1% level of significance to determine whether there is evidence of a positive correlation between vibration frequency and cabin noise. The critical value for the product moment correlation coefficient at the 1% significance level for a sample size of 50 is 0.3281.
355 exam-style questions on OCR (MEI) A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 Process and language of hypothesis testing, 2.5.2 When to apply 1-tail and 2-tail tests, 2.5.3 Significance level and incorrect rejection, 2.5.4 Null and alternative hypotheses (binomial), 2.5.5 Conduct a binomial hypothesis test, 2.5.6 Critical and acceptance regions (binomial), 2.5.7 Distribution of the sample mean (A-level only), 2.5.8 Hypothesis test for a single mean (A-level only), 2.5.9 Critical and acceptance regions (mean) (A-level only), 2.5.10 Correlation as closeness to a straight line (A-level only), 2.5.11 Inference using a correlation coefficient (A-level only), and 2.5 Statistical Hypothesis Testing. Each one has a worked solution and a mark scheme showing where the marks go.