Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • The mean of a set of 50 observations is 80. It was later discovered that two observations, 85 and 88, were incorrectly recorded as 65 and 68. What is the correct mean?  <div clas

The mean of a set of 50 observations is 80. It was later discovered that two observations, 85 and 88, were incorrectly recorded as 65 and 68. What is the correct mean?

 

Option: 1

79.6


Option: 2

80.2


Option: 3

80.7


Option: 4

81.4


Answers (1)

best_answer

To find the correct mean, we need to adjust the two incorrectly recorded observations and recalculate the mean.

The sum of the original 50 observations is 80 \times 50 = 4000.

We need to subtract the incorrect values (65 and 68) and add the correct values (85 and 88) to the sum.

Corrected sum = (4000 - 65 - 68) + 85 + 88 = 4000 - 65 - 68 + 85 + 88 = 4040.

The correct mean is the corrected sum divided by the number of observations (50).

Corrected mean = 4040 / 50 = 80.8.

Therefore, the correct mean is 80.8.

Among the given options, 80.7 is the closest to the correct mean.

 

Posted by

vishal kumar

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2025: NIT Rourkela cut-offs for CSE, chemical engineering drop; last years' closing ranks
anam-khan

JEE Main 2025 Live: NTA exam city slip at jeemain.nta.nic.in soon; session 1 schedule
anam-khan

JEE Main 2025 schedule out for session 1; paper 1 from January 22

Latest Question