Suppose Charlene Brewster has times (in seconds) of 8.4,8.6,8.3,8.5,8.7,8.5 and a performance rating of 110%. a) For a given allowance factor of 15%, the standard time for the operation = seconds (round your response to two decimal places). b) For a given allowance factor of 18%, the standard time for the operation = seconds (round your response to two decimal places)