Question
The mean of a set of 120 observations is 80.10 is
subtracted from each observation and each of the corresponding result is divided by 7. What is the mean of the new set?Solution
Total of 120 observation = 120 × 80 ⇒ 9600 After decreasing new total = 9600 - 10 × 120 ⇒ 8400 Now, After dividing each term by 7 new total = 8400/7 = 1200 Now, New mean = 1200/120 ⇒ 10 ∴ The mean of the new set is 10
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