First question:
a) Plot the point (4, 2600) on the graph.
b) The relationship is linear with the older the car, the lesser value it has (the line has a negative slope).
c) To estimate the value, plot these points on a sheet of graph paper, draw what you feel is the line through these data points that best represents the data (a "best-fit" regression line), and find the y-value of the point that is (3.5, something).
Second question:
a) All of the points, except for one, is on a line from the lower left to the upper right. There is one point that is plotted away from the others, above the others, it is point (140, something) -- this point is the outlier.
b) The other points form a linear, positive, relationship (positive because the slope of the regresstion line is positive).
c) Plot these points on a sheet of graph paper, draw what you feel is the best-fit line for these points, and then find where the line y = 45 kg intercepts this line -- this will give you his predicted height.