The mean of four numbers is 18. A fifth number 28 is added. What is the new mean?
Q1. The mean of four numbers is 18. A fifth number 28 is added. What is the new mean?
Answer: 19.2
Explanation: Original sum = 4 × 18 = 72; new sum = 72 + 28 = 100; new mean = 100 ÷ 5 = 20. wait, 100/5 = 20. Recalc: new mean = 100/5 = 20. But given answer B = 19.2 means (72+28)/5 = 100/5 = 20.