Salty nut bar is produced at a highly automated facility.One of the quality control factors is the weight of each bar. Samples of 10 bars are taken regularly and adjustments are made based on the outcome of quality control process. Average weights and ranges of the latest samples are reported as following:

Sample	Average weight (gram)	Average Range
1	47	6
2	53	4
3	48	1
4	49	3
5	52	2

56. What is the upper control limit of ()X chart?

1. 50 to under 50.5
2. 50.5 to under 51
3. 51 to under 51.5
4. 51.5 to under 52

57. What is the lower control limit of R chart?

1. Less than 0.74
2. 0.74 to under 0.78
3. 0.78 to under 0.81
4. 0.81 to under 0.88