Use the following information to answer questions 13-15:

Apple Quaker nut bar is produced at a highly automated facility.One of the quality control factors is the weight of each bar. Samples of 8 bars are taken regularly and adjustments are made based on the outcome of quality control process. Average weights and ranges of the latest 10 samples are reported as following:

Sample	Average weight (gram)	Average Range
1	49	4
2	54	5
3	54	7
4	53	5
5	54	7
6	46	3
7	51	7
8	49	6
9	47	4
10	46	4

1. What is the lower control limit of