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 11 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 4 5 5 3 4
Element 2 90 9 11 8 11 10
Element 3 80 7 6 7 7 8
The time per unit customer served is ------ minutes. ?(Enter your response rounded to two decimal? places.)