How do you calculate upper and lower control limits?

Consider the following samples taken from a process. Calculate the upper control limit for the R chart. {| |- |

Sample 1 211 206 203 213 Sample 2 208 202 207 202 Sample 3 207 208 199 201 Sample 4 209 207 200 205 Sample 5 205 198 207 204 Sample 6 209 204 198 212 Sample 7 208 198 204 207 Sample 8 203 202 198 208 Sample 9 210 211 202 201 Sample 10 199 202 208 210

12

14

15

16

17

18

20

22 |}