An initial time study was done on a process with the following results (in minutes). Based on the data obtained so far, assuming an allowance of 15 percent of the normal time, what do you estimate for the time per customer served, based on this preliminary sample? (Round all intermediate calculations to two decimal places.) Element Performance Rating Obs 1 Obs 2 Obs 3 Obs 4 Obs 5 Element 1 130 3 5 6 6 5 Element 2 120 11 10 9 8 9 Element 3 80 7 6 8 6 6