The arithmetic mean of 100 observations is found to be 50. If at the time of…
2013
The arithmetic mean of 100 observations is found to be 50. If at the time of computations two items are wrongly taken as 30 and 29 instead of 3 and 92, the correct mean is:
- A.
50.20
- B.
50.36
- C.
51.15
- D.
51.45
Attempted by 7 students.
Show answer & explanation
Correct answer: B
Step 1: The incorrect sum of 100 observations is calculated as 100 × 50 = 5000.
Step 2: The two items were wrongly taken as 30 and 29 instead of 3 and 92.
Step 3: The difference in sum due to the error is (3 + 92) - (30 + 29) = 95 - 59 = 36.
Step 4: The correct sum is 5000 + 36 = 5036.
Step 5: The correct mean is 5036 / 100 = 50.36.
हिन्दी उत्तर:
चरण 1: 100 प्रेक्षणों का गलत योग 100 × 50 = 5000 है।
चरण 2: दो वस्तुओं को 3 और 92 के स्थान पर 30 और 29 लिया गया है।
चरण 3: त्रुटि के कारण योग में अंतर (3 + 92) - (30 + 29) = 95 - 59 = 36 है।
चरण 4: सही योग 5000 + 36 = 5036 है।
चरण 5: सही समान्तर माध्य 5036 / 100 = 50.36 है।