Examine the case mix data set below. Using the correct formula, determine the Case Mix Index $($CMI$)$ to report. Which answer represents the correct CMI?$$

DRGNumber casesDRG relative weightTotal DRG relative weightX$200\mathrm{.}500010\mathrm{.}0000$Y$121\mathrm{.}500018\mathrm{.}0000$Z$51\mathrm{.}00005\mathrm{.}0000$

Group of answer choices

$1\mathrm{.}000$

$5\mathrm{.}000$

$1\mathrm{.}212$

$0\mathrm{.}8919$