Use the fact that the resistance of a wire carrying an elect…

Use the fact that the resistance of a wire carrying an electrical current is directly proportional to its length and inversely proportional to its cross-sectional area. ​ A 13-foot piece of copper wire produces a resistance of 0.2 ohm. Use the constant of proportionality k = 0.000833 to find the diameter of the wire. ​ (Round the answer to three decimal places.) ​

The simple interest on an investment is directly proportiona…

The simple interest on an investment is directly proportional to the amount of the investment. By investing $6500 in a certain certificate of deposit, you obtained an interest payment of $130.00 after 1 year. Determine a mathematical model that gives the interest, I, for this CD after 1 year in terms of the amount invested, P.