Cost-to-charge ratio (the percentage of the amount billed that represents the actual cost) for inpatient and outpatient services at 11 Oregon hospitals is shown in the following table (Oregon Department of Health Services, 2002). A scatterplot of the data is also shown.

Cost-to-Charge Ratio Hospital Outpatient Care Inpatient Care 162 80 266 76 363 75 451 62 5 75 100 665 88 756 64 845 50 948 54 10 71 83 11 54 100 The least-squares regression line with y inpatient costto-charge ratio and x outpatient cost-to-charge ratio is y^ 5 21.1 1 1.29x.

a. Is the observation for Hospital 11 an influential observation? Justify your answer.

b. Is the observation for Hospital 11 an outlier?

Explain.

c. Is the observation for Hospital 5 an influential observation? Justify your answer.

d. Is the observation for Hospital 5 an outlier?

Explain.