Sarah owns an ice cream parlour. Over the course of 12 days in the summer, she records the number of hours of sunshine, hhh, and the volume of ice cream sold, V V\,V litres. The product moment correlation coefficient for these data is calculated as 0.72.
Stating your hypotheses clearly and using a 5% significance level, test whether there is a positive correlation between hours of sunshine and ice cream sales.
Sarah suggests that a linear regression model could be used to model the data.
State, giving a reason, whether or not the correlation coefficient is consistent with Sarah's suggestion.
State, giving a reason, which variable would be the explanatory variable.
Sarah calculated the linear regression equation as V=15.5+4.2hV = 15.5 + 4.2hV=15.5+4.2h
Give an interpretation of the gradient of this regression equation.
Practise Edexcel A Level Maths Regression, Correlation and Hypothesis Testing with exam-style questions for A Level Maths. 100 questions covering Exponential Models, Measuring Correlation, and Hypothesis Testing for Zero Correlation, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.