Final answer:
To increase the mean of 7 numbers by 4, the sum must increase by 28, which means each of the 7 numbers is increased by 4 for a total increase of 28.
Step-by-step explanation:
To increase the mean of 7 numbers by 4, the sum of the 7 numbers would have to increase by 28.
To increase the mean of 7 numbers by 4, the sum of the 7 numbers would have to increase by 28. The correct option is (a) 28.
A mean is calculated by dividing the total sum of all numbers by the quantity of numbers. If the mean of 7 numbers needs to be increased by 4, you multiply the increase per number (4) by the total number of figures (7). 4 (increase) × 7 (numbers) = 28. This results in the total sum needing to increase by 28 to achieve the desired increase in the mean. Therefore, to raise the mean by 4, you would add 4 to each of the 7 numbers, thus increasing the overall sum by 28.
Step by step explanation
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- Identify the desired increase in the mean, which is 4.
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- Count the total number of numbers, in this case, 7.
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- Multiply the number of figures by the increase in mean: 4 × 7 = 28.
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- Conclude that the sum of the numbers must increase by 28.