Question

consider the data set 5, 8, 12, 18, 22, 30. removing which number from the data set would cause the median to decrease? 18 12 8 5

Explanation:

Step1: Find original median

Original data: 5,8,12,18,22,30 (6 numbers). Median = $\frac{12+18}{2}=15$.

Step2: Test removing 18

New data:5,8,12,22,30 (5 numbers). Median = 12 (12 < 15).

Step3: Test removing 12

New data:5,8,18,22,30. Median=18 (18>15).

Step4: Test removing 8

New data:5,12,18,22,30. Median=18 (18>15).

Step5: Test removing5

New data:8,12,18,22,30. Median=18 (18>15).

Answer:

18