9.

A pizza delivery service wants to track their delivery times. They take eight samples of four deliveries and record the following data. What are the upper and lower control limits of their R-chart? (Note: Although it looks similar, the data in the table below is different from the data in the table relating to the UCL and LCL for the X-bar chart.)

Sample #	1	2	3	4	5	6	7	8
Item #1	21.1	20.2	24.1	22.6	21.2	20.0	22.0	20.2
Item #2	21.7	20.6	21.0	22.1	24.1	24.2	24.6	24.9
Item #3	23.5	24.9	23.2	23.0	20.6	22.8	23.4	22.8
Item #4	20.0	23.5	24.8	25.0	20.7	23.2	23.3	24.5

Group of answer choices

7.0, 0.5

9.3, 0.0

8.5 0.0

10.1, 0.0