Question

The relation between the cost of a certain gem and its weight is linear. In looking at two gems, we find that one of the gems weighs 0.3 carat and costs $3,457, while the other gem weighs 0.5 carat and costs $4,373. Find a linear function that relates the price of a gem, C(x), to its weight, x, treating weight as the independent variable.
I appreciate anyone who can help me. I will be reporting any foolish answers.

Answer 1

Treat each of the rings as a point on a graph the point being (carat, Cost ring)
Knowing this we have 2 points which we need to form a line. 
(0.3, 3457); (0.5, 4373)  From this we can for a slope and then an equation.
slope =