Q19 of 79 Page 25

The mean of 5 numbers is 18. If one number is excluded, their mean is 16. Find the excluded number.

The mean of 5 numbers is 18

Then, the sum of 5 numbers = 5 * 18


= 90


If the one number is excluded


Then, the mean of 4 numbers = 16


Therefore, sum of 4 numbers = 4 * 16


= 64


Excluded number = 90 – 64


= 26


More from this chapter

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The mean weight per student in a group of 7 students is 55 kg. The individual weights of 6 of them (in kg) are 52, 54, 55, 53, 56 and 54. Find the weight of the seventh student.

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The mean weight of 8 numbers is 15. If each number is multiplied by 2, what will be the new mean?

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The mean of 200 items was 50. Later on, it was discovered that the two items were misread as 92 and 8 instead of 192 and 88. Find the correct mean.

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Find the values of n and in each of the following cases:

(i) = -10 and = 62


(ii) = 30 and = 150