Compute the arithmetic mean: Find the average of the five numbers 308, 142, 160, 245, and 25.
Aptitude
Average
Difficulty: Easy
Choose an option
Answer
Correct Answer: 176
Explanation
Introduction / Context:Simple average computation requires adding all values and dividing by the count. This tests care with multi-digit addition and division by a small integer.
Given Data / Assumptions:
- Numbers: 308, 142, 160, 245, 25
- Count = 5
Concept / Approach:Average = sum of values / number of values. Keep arithmetic neat and double-check totals.
Step-by-Step Solution:
Sum = 308 + 142 + 160 + 245 + 25Sum = 880Average = 880 / 5 = 176Verification / Alternative check:Group numbers for easy addition: (308 + 142) = 450, (160 + 245) = 405, plus 25 gives 450 + 405 + 25 = 880. Divide by 5 gives 176.
Why Other Options Are Wrong:
- 178, 175, 174, 172: all differ from the exact division of 880 by 5.
Common Pitfalls:Mistakes typically occur in addition. Verifying with regrouping helps avoid carry errors.
Final Answer:176