In an investigation into prediction using the stars and planets a celebrated astrologist, Horace Cope predicted the ages at which thirteen young people would first marry. The complete data, of predicted and actual ages at first marriage, are now available and are summarised in the table.
Person A B C D E F G H I J K LM
Predicted age x (years) 24 30 28 36 20 22 31 28 21 29 40 25 27
Actual age y (years) 23 31 28 35 20 25 45 30 22 27 40 27 26
(a) Draw a scatter diagram of these data.
(b) Calculate the equation of the regression line of y on x and draw this line on the scatter diagram.
(c) Comment upon the results obtained, particularly in view of the data for person G. What further action would you suggest?
