A study was conducted to find the relationship between the age at which a child first speaks and their level of intelligence as teenagers. The following table shows the ages at which some teenagers first spoke, and their results in an aptitude test:
A researcher plotted the life expectancy of a group of men against the number of cigarettes they smoke a day. The results were recorded and the correlation coefficient, r, was found to be −0.88. Describe the correlation between the life expectancy of a man and the number of cigarettes smoked per day.
A study was conducted to find the relationship between the age at which a child first speaks and their level of intelligence as teenagers. The following table shows the ages at which some teenagers first spoke, and their results in an aptitude test:
Calculate Spearman's rank coefficient, to three significant figures.
State what conclusions you can make from Spearman's rank coefficient.
A student was performing an experiment to study the relationship between the current and voltage through a resistor. He noted his results in the following table:
Calculate Spearman's rank coefficient, to three significant figures.
State what conclusions you can make from Spearman's rank coefficient.
The table lists the time taken to sprint 400 metres by runners who all ran in different temperatures as part of a study:
State the number of runners that were tested in the study.
Calculate Spearman's rank correlation coefficient, to three significant figures.
Jordano measures his heart rate at various times while running. Time is x and Heart Rate is y. The data is shown below in the table:
Write down the value of the Pearson's product-moment correlation coefficient, r, to three significant figures.
Describe the correlation between temperature and sprint time ranking for the data.
Using the value of r, interpret the relationship between time and heart rate.
Write down the regression line equation, giving all parameters to three significant figures.
Use your regression equation to estimate Jordano's heart rate 7 minutes into his run.
State whether this estimate is reliable. Justify your answer.
