Question

the mean of 7 numbers is 42 if each number is reduced by 3 find the new mean​

Answer 1

Answer:

39

Step-by-step explanation:

the mean of 7 numbers is 42

Sum of the numbers = 42×7 = 294

if each number is reduced by 3, the total reduction = 7×3 = 21

new sum of the Numbers = 294 - 21 = 273

new mean = new sum/7 = 273/7 = 39

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you don't need to do all the calculation. Just remember that:

1. if all the numbers are increased by x, new mean= mean+x.

2. if all the numbers are decreased by x, new mean = mean-x.

3. if all the numbers are multiplied by x, new mean = mean×x.

4. if all the numbers are divided by x, new mean = mean÷x.

In the question, all numbers were decreased by 3, so new mean = 42 - 3 = 39