The Statistics Bureau processes test scores in one pass each.
Implement three methods over an int[] scores (each 0–100; the array is
never empty):
1. int average(int[] scores) — the mean **rounded down** to a whole
number ((int) truncation is acceptable and expected).
2. int passRate(int[] scores) — the percentage of scores ≥ 60, rounded
down (an integer 0–100, not a double).
3. int secondLargest(int[] scores) — the second-largest DISTINCT value;
every score is guaranteed to appear at least twice or the array is
guaranteed to hold at least two distinct values — when all values are
identical, return that value itself.
One loop per method (no Arrays.sort — this is a loops exercise), each
carrying only the state it needs. average({70, 80, 91}) is 80;
passRate({70, 80, 91}) is 100; secondLargest({90, 90, 85}) is 85.
Difficulty: beginner