In an experiment with 15 observations on x, the following results were available \[\sum {{x}^{2}}=2830,\,\,\sum x=170\]. One observation that was 20, was found to be wrong and was replaced by the correct value 30. Then, the corrected variance is
AIEEE Solved Paper-2003
A)78.00
B) 188.66
C) 177.33
D) 8.33
Correct Answer:
A
Solution :
Variance Given, N = 15 One observation 20 was replaced by 30, then Variance,