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Probability

Question

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The mean of 40 observations was 160. It was detected on rechecking that the value 165 was wrongly copied as 125. Find the correct mean.

Solution

∵ Mean of 40 observations = 160
∴ Sum of 40 observations = 160 x 40 = 6400 Corrected sum of 40 observations
= 6400 - 125 + 165
= 6440
$therefore$ Correct mean = $6440 over 40 equals 161$

Some More Questions From Probability Chapter

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