A Certain HMO Is Attempting to Show the Benefits of Managed

A certain HMO is attempting to show the benefits of managed care to an insurance company. The HMO believes that certain types of doctors are more cost-effective than others. One theory is that
Certification level is an important factor in measuring the cost-effectiveness of physicians. To
Investigate this, the HMO obtained independent random samples of 25 physicians from each of the
Three certification levels-Board certified (C) ; Uncertified, board eligible (E) ; and Uncertified, board
Ineligible (I) -and recorded the total per-member, per-month charges for each (a total of 25
Physicians) . In order to compare the mean charges for the three groups, the data will be subjected
To an analysis of variance. Write the null hypothesis tested by the ANOVA.

A) $H _ { 0 } : \beta _ { 1 } = \beta _ { 2 } = \beta _ { 3 } = 0$
B) $H _ { 0 } : p _ { 1 } = p _ { 2 } = p _ { 3 }$
C) $H _ { 0 } : \mu _ { \mathrm { C } } = \mu _ { \mathrm { E } } = \mu _ { \mathrm { I } } = 0$
D) $H _ { 0 } : \mu _ { \mathrm { C } } = \mu _ { \mathrm { E } } = \mu _ { \mathrm { I } }$