Math, asked by abhishekdas9646, 1 year ago

the mean and standard deviation of 100 observations were calculated as 40 and 5.1 resp. by a student who took by mistake 50 instead of 40 for one observation. what are correct mean and standard deviation?

Answers

Answered by Anonymous
8

Mean=Sum of all observations/Number of obervations

Before realizing mistake

40=Sum of all observations/100

Sum of all observations=400

After realizing mistake

Replace 40 by 50. But How? We cannot replace them until we have all observations but we have sum of observations which will get effected by replacing 40 by 50. So new sum will be 10 less

Sum of all observations=390

New mean=390/100=39

Use formula for SD where they used sum, sum of squares.

Answered by Aditiiiiiiiiiii
15

Answer:

Correct SD = 5

Step-by-step explanation:

Formula Explanation

• Correct Mean = Summation X (Wrong) - Incorrect Value + Correct Value

/ No. of Observations

Attachments:
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