1. Questions have arisen about the strength of IVs. As a result the pharmacy has started randomly testing IVs to determine if they contain the correction proportion of medicine and saline. The pharmacy tests six IVs every day. Assume the recommended mixture is 20 parts medicine to 1,000 parts saline. Samples for the last eight days are shown next.

SAMPLES Observation 1 2 3 4 5 6 7 8 1 12 27 20 18 26 24 27 30 2 18 16 22 17 20 19 16 18 3 20 28 23 22 19 21 23 22 4 24 23 22 28 23 20 22 25 5 14 19 20 23 22 21 23 21 6 13 18 25 23 22 24 23 19

a. Create X − and R charts.

b. Evaluate both graphs. Are there any concerns that should be explored? Is the IV mixing process performing adequately?