The range of the top plot, hours spent by 13-15 year olds, is found by subtracting the highest value, 34, and the lowest value, 21. 34-21=13.
The mean of the top plot is found by adding together all of the data points and dividing by 10 (the number of data points):
The range of the bottom plot, minutes spent online by 16-18 year olds, is found by subtracting the highest value, 36, and the lowest value, 12. 36-12=24.
The mean of the bottom plot is found by adding together all of the data points and dividing by 11 (the number of data points):
The mean of the top plot is found by adding together all of the data points and dividing by 10 (the number of data points):
The range of the bottom plot, minutes spent online by 16-18 year olds, is found by subtracting the highest value, 36, and the lowest value, 12. 36-12=24.
The mean of the bottom plot is found by adding together all of the data points and dividing by 11 (the number of data points):