A student calculated the mean of 5 numbers as 45.3. While rechecking his working, he discovered that his total was short by 20.5. What is the correct mean of the 5 numbers?
A
49.4
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
The student calculated the mean as 45.3 for 5 numbers.
Therefore, the **wrong total (sum) he used was:
45.3 × 5 = 226.5
He discovered that his total was short by 20.5.
This means the actual (correct) sum is:
226.5 + 20.5 = 247
Correct mean = Correct sum ÷ Number of numbers
247 ÷ 5 = 49.4
Source: WAEC / JAMB / NECO Classroom Archive (Record #77195)