A hospitals records show that the cost of carrying out health checks in the last five accounting periods have been as follows:

Period	No. of patients seen	Total costs ($)
1	650	17,125
2	940	17,800
3	1260	18,650
4	990	17,980
5	1150	18,360

Required:

Using the high-low method and ignoring inflation, what are the estimated cost of carrying out health checks on 850 patients in period 6?