A bus company, Neville's Coaches, competes with the train operator. Gary, Neville's Coaches operations manager feels their service is at a disadvantage because road journeys are more unpredictable. But, by restricting the number of stops, the bus times are now approximately equal to the train times over the same route. Over a period of 5 days the duration of the bus service was recorded 8 times each day. The average, maximum and minimum times obtained for each successive day are given in the table below. 4) What is the difference between the Upper and Lower Control limits for the means chart, to 2 decimal places? 1.99 3.06 5.22 4.39 5) What is the difference between the Upper to Lower Control limits for the ranges chart? 7.14 B.65 12.09 (infinity) 6) Which of the following would NOT normally be considered as a 'cost of quality'? Product failure costs Prevention costs Marketing costs Inspection costs