The manager of the main laboratory facility at Elmhurst Health Center is interested in being able to predict the overhead costs each month for the lab. The manager believes that total overhead varies with the number of lab tests performed but that some costs remain the same each month regardless of the number of lab tests performed. The lab manager collected the following data for the first seven months of the year.

Use thehigh-low method to determine thelaboratory's cost equation for total laboratory overhead. Use your results to predict total laboratory overhead if 3,100 lab tests are performed next month.