A Certain HMO Is Attempting to Show the Benefits of Managed

Multiple Choice

A certain HMO is attempting to show the benefits of managed health care to an insurance company. The HMO believes that certain types of doctors are more cost-effective than others. One theory is that both primary specialty and whether the physician is a foreign or USA medical school graduate are an important factors in measuring the cost-effectiveness of physicians. To investigate this, the president obtained independent random samples of 40 HMO physicians, half foreign graduates and half USA graduates, from each of four primary specialties?General Practice (GP) , Internal Medicine (IM) , Pediatrics (PED) , and Family Physician (FP) ?and recorded the total per-member, per-month charges for each. Thus, information on charges were obtained for a total of n = 160 doctors. The sample mean charges for each of the eight categories are shown in the table. $$\begin{array} { c c c } \hline \text { Primary Specialty } & \text { Foreign Grad } & \text { USA Grad } \\\hline \text { GP } & 39.80 & 42.20 \\\text { IM } & 55.80 & 53.50 \\\text { PED } & 23.50 & 25.30 \\\text { FP } & 38.00 & 41.80 \\\hline\end{array}$$ What type of design was used for this experiment?

A) 4 x 2 factorial design with 20 replications
B) completely randomized design with eight treatments
C) completely randomized design with two treatments
D) 2 x 2 factorial design with 160 replications