Mathematics
Find the mean of 25 given numbers when the mean of 10 of them is 13 and the mean of the remaining numbers is 18.
Measures of Central Tendency
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Answer
Given, mean of 10 numbers is 13.
∴ Sum of 10 terms = 13 × 10 = 130.
Given, mean of 15 numbers is 18.
∴ Sum of 15 terms = 15 × 18 = 270.
Sum of 25 terms = 130 + 270 = 400.
Hence, the mean of 25 numbers is 16.
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