4. B and Care points on a circle, centre o TCD is a tangent to the circle.
Angle BAC 54
10.
8
[2]
(a) Find angle BOC, giving a reason for your answer
(b) When is the origin, the position vector of point is
Work out the gradient of the radius OC.
(C)D is the point (7, k).
10
Find the value of k.

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?