Answers

2016-04-05T18:05:00+05:30
Range-HV -LV
= 22-x=9
=  x=13

so the fourth no. is 13
1 5 1
2016-04-05T18:27:56+05:30
Range of a set is defined as the difference of highest value and lowest value in the set.
Let
22 be the highest value then the lowest value = 22 - 9 = 13
13 is the fourth number
Let
18 is the lowest number then the highest value = 18 +9 = 27
27 is the fourth number

therefore the fourth number can be 13 or 27
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