Robin wanted to know if the age partition chosen for her data was the best fit for her 30 case, 90% Class 1, 10% Class 0 partition. She completed the Gini impurity index with the results of (Age

Question

Robin wanted to know if the age partition chosen for her data was the best fit for her 30 case, 90% Class 1, 10% Class 0 partition. She completed the Gini impurity index with the results of (Age < 32) = 0.2034 and (Age $\ge$ 32) = 0.2786. What is the weighted combination and what did partition at Age 32 produce?
A) Robin was able to reduce the Gini index from 0.2786 to 0.2507, confirming the best split for age.
B) Robin was able to reduce the Gini index from 0.2786 to 0.20, confirming the best split for age.
C) Robin was able to reduce the Gini index from 0.2786 to 0.2109, confirming the best split for age.
D) Robin realized with the 0.2507 weighted average, the age split was not the best split for the age range.

Quizplus · Accepted Answer

The weighted combination of the Gini impurity index for the two groups (Age < 32 and Age ≥ 32) would be calculated based on the proportion of cases in each group. Given the Gini impurities of 0.2034 and 0.2786 for the two groups, respectively, and knowing the distribution of cases (90% Class 1, 10% Class 0), we can infer that the weighted Gini index would be a value that reflects a reduction from the initial impurity, indicating a better split. The correct calculation would result in a weighted average that is lower than the initial, showing improvement. Option C provides a specific value (0.2109) that represents such an improvement, confirming it as the correct choice.

Robin Wanted to Know If the Age Partition Chosen for Her