The table below shows the corresponding values of two variables X and Y.
| X | 33 | 31 | 28 | 25 | 23 | 22 | 19 | 17 | 16 | 14 |
| Y | 4 | 6 | 4 | 10 | 12 | 10 | 14 | 15 | 18 | 22 |
(a) Plot a scatter diagram to represent the data.
(b) Calculate (bar{x}), the mean of X and (bar{y}), the mean of Y.
(c) Draw the line of best fit to pass through ((bar{x}, bar{y})).
(d) From your graph in (c), determine the (i) relationship between X and Y ; (ii) value of Y when X is 24.
Explanation
| X | 33 | 31 | 28 | 25 | 23 | 22 | 19 | 17 | 16 | 14 | 228 |
| Y | 4 | 6 | 4 | 10 | 12 | 10 | 14 | 15 | 18 | 22 | 115 |
(b) (bar{x} = frac{sum X}{N} = frac{228}{10} = 22.8)
(bar{y} = frac{sum Y}{N} = frac{115}{10} = 11.5)
(c) See graph above.