- ABoth A and R are true, and R correctly explains A
- BBoth A and R are true, but R does not explain A
- CA is true, R is false
- DA is false, R is true
Step-by-Step Solution
Middle two of 1,2,3,4 are 2 and 3, so median = (2+3)/2 = 2.5 (A true). The rule about even counts (R) is exactly why A is true.
Answer: A) Both A and R are true, and R correctly explains A
Key idea: Median — the middle value
Step 1: arrange the data in **ascending order**. Step 2: find the middle.
- **Odd count**: the middle value is the median. Marks 3, 5, 7, 9, 11 → median = 7.
- **Even count**: average the two middle values. Marks 3, 5, 7, 9 → middle two are 5 and 7 → median = (5+7)/2 = 6.
Median ignores extreme values; it tells you the 'typical middle' regardless of outliers.