Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The mean of 20 observations is $15 .$ On checking, it was found that two observations were wrongly copied as 3 and 7 wrong observations are replaced by correct value 8 and 4, then the correct mean is
MathematicsStatisticsNDANDA 2013 (Phase 2)
Options:
  • A 15
  • B $15.15$
  • C $\quad 15.35$
  • D 16
Solution:
2515 Upvotes Verified Answer
The correct answer is: $15.15$
Sum of all observations $=20 \times 15=300$ Sum of correct observations $=300-(3+6)+(8+4)=303$
Correct mean $=\frac{303}{20}=15.1$ ?

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.