Question

X bar and standard deviation of a series of 80 terms is 50 and 5 but later on it was found that a term 17 was wrongly included as 71 find correct x bar and standard deviation​

Answer 1

Answer:

Step-by-step explanation: first get right mean

Then using this formula √[(incorrect {x²/n)-(incorrect {x/n)²]

then u can easily get incorrect{x² by squaring both sides

now from incorrect{x² subtract wrong term's Square (here 71²) and add right term square (here 17²)

and now we correct {x²

we already have ({x/n) i.e. A.M.

now put these in formula back and S.D. will be found

√[({x²/n)-({x/n)²] = S.D.

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