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Let the mean and variance of the frequency distribution x : x1 = 2 x2 = 6 x3 = 8 x4 = 9 f : 4 4 0 2 be 6 and 6.8 respectively. If x3 is changed from 8 to 7, then the mean for the new will be:
- 4
- 5
- 17/3
- 16/3
Correct answer: 5
Solution
The mean is calculated by taking the sum of the products of each value and its frequency, then dividing by the total frequency. Changing x3 from 8 to 7 reduces the total sum of the products, leading to a new mean of 5 when recalculated with the updated frequencies.
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