For positive variables x x\,x and yyy, the correlation coefficient between lnx \ln x\,lnx and lny \ln y\,lny is 0.992. The regression line is lny=1.80+0.650lnx\ln y=1.80+0.650\ln xlny=1.80+0.650lnx.
Explain why the data support a power model for y y\,y in terms of xxx.
Use the fitted regression line to estimate y y\,y when x=4x=4x=4. Give your answer to 3 significant figures.
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.