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Question
Arithmetic mean of 10 observations was found to be 22. If one more observation 44 was to be added to the data, what would be the new mean?
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Solution
Arithmetic mean of 10 observation is 22
Arithmetic mean = `"Sum of all observations"/"Number of observations"`
22 = `"Sum of 10 observations"/10`
Sum of 10 observations = 22 × 10 = 220
Now if new number is added, then
Mean of 11 observations = `("Sum of 10 observation" + 44")/11`
= `(220 + 44)/11`
= `264/11`
= 24
New mean = 24
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