Chris is investigating the relationship between the length of time an employee has worked at his company, x x\,x years, and the time it takes that employee to complete a particular task, y y\,y hours.
Chris records the time taken by a random sample of 12 employees. The product moment correlation coefficient between x x\,x and y y\,y for this sample is -0.47.
For n=12n = 12n=12, the critical value for a one-tailed test at the 5% level for the population correlation coefficient is 0.4973.
Carry out a hypothesis test at the 5% significance level to determine whether there is a negative correlation between the length of time an employee has worked at the company and the time taken to complete the task.
244 exam-style questions on AQA A Level Maths 2.2 L: Data presentation and interpretation, covering 2.2.1 Single-variable data diagrams, 2.2.2 Scatter diagrams and correlation, 2.2.3 Central tendency, variation and standard deviation, 2.2.4 Outliers and cleaning data, and 2.2 L: Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.