Evaluate the two proposed answers. Which are supported? I. the geometric mean of positive numbers 9 and 16 — the numerical answer: 6. II. the new average when 50 is added to four numbers with average 30 — the numerical answer: 34.
Correct answer: A
I is incorrect: the geometric mean of positive numbers 9 and 16 → 12. The positive square root of 9×16 is 12. II is correct: the new average when 50 is added to four numbers with average 30 → 34. The total becomes 120+50=170 across five numbers.