Test a Hypothesis Regarding Three or More Means Using One $\mathrm { H } _ { 0 } : \mu _ { \mathrm { C } } = \mu _ { \mathrm { E } } = \mu _ { \mathrm { I } }$

Test a Hypothesis Regarding Three or More Means Using One -Way ANOVA
-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 19 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 19 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) $\mathrm { H } _ { 0 } : \mu _ { \mathrm { C } } = \mu _ { \mathrm { E } } = \mu _ { \mathrm { I } }$
B) $\mathrm { H } _ { 0 } : \beta _ { 1 } = \beta _ { 2 } = \beta _ { 3 } = 0$
C) $\mathrm { H } _ { 0 } : \mu _ { \mathrm { C } } = \mu _ { \mathrm { E } } = \mu _ { \mathrm { I } } = 0$
D) $\mathrm { H } _ { 0 } : \mathrm { p } 1 = \mathrm { p } 2 = \mathrm { p } 3$