4. The table shows the cost for ordering a certain number of pizzas. What is 1 the value of x if the cost is proportional to the number of pizzas ordered? * Pizzas Ordered 4 Cost $19.98 $29.97 $39.96 O $9.99 $29.97 O $49.95 O $59.94

15. For each table below, select whether the data represents a function. If it does represent a function, determine if the function is increasing, decreasing or constant.A. {(3,164), (4,136), (5,100), (6,56), (7,4), (8,−56)}{(3,164), (4,136), (5,100), (6,56), (7,4), (8,-56)} Select an answer Increasing Decreasing Constant Not a Function  B. {(3,36), (4,64), (5,100), (6,144), (7,196), (8,256)}{(3,36), (4,64), (5,100), (6,144), (7,196), (8,256)} Select an answer Increasing Decreasing Constant Not a Function  C. {(3,−7), (4,−7), (5,−7), (6,−7), (7,−7), (8,−7)}{(3,-7), (4,-7), (5,-7), (6,-7), (7,-7), (8,-7)} Select an answer Increasing Decreasing Constant Not a Function  D. {(3,23), (4,27), (5,31), (6,35), (4,39), (8,43)}{(3,23), (4,27), (5,31), (6,35), (4,39), (8,43)} Select an answer Increasing Decreasing Constant Not a Function

An economist want to determine the relation between one’s FICO score, x, and the interest rate of a 36-month auto loan, y. The given data represent the interest rate (in percent) a bank would offer on a 36-month auto load for various FICO scores. Credit Score;x Interest Rate (percent);y 545 18.982 595 17.967 640 12.218 675 8.612 705 6.68 750 5.15 Find the least-squares regression line treating the FICO score as the explanatory variable and the interest rate as the response variable. Predict the interest rate a person would pay if their FICO score were the median score of 723.

A copy machine dealer has data on the number x of copy machines at each of 89 customer locations and the number y of service calls in a month at each location. r was found to be 0.86. About what percent of the variation in the number of service calls is explained by the linear relation between the number of service calls and number of machines? *       86%       93%       74%       43%       none of the above