Question

3,x,5,5,9,8,15,13 place of x given series
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Answer 1

Answer:

$The \: mode \: is \: the \: value \: which \: occurs \: the \: most \: often \: in \: a \: given \: set \: of \: data.  \\ </p><p>In \: the \: data \: set \: provided \: here, \: the \: mode \: is \: 15, \: hence \: 15 \: should \: occur \: the \: most \: number \: of \: times. \: </p><p>10,11,12,10,15,14,15,13,12,x,9,7</p><p> \: Excluding x and \: arranging \:  these \: numbers \: in \: ascending \: order, \: </p><p>7,9,10,10,11,12,12,13,14,15,15</p><p>Here \: 10, 12 and \: 15 \: are \: occurring \: twice. </p><p></p><p>Since \: 15 \: is \: the \: mode, \: it \: should \: occur \: more \: than \: twice. </p><p></p><p>Therefore, \: the \: value \: of x should \: be \: 15 \: if \: the \: value \: of \: mode \: is \: 15.</p><p></p><p>$

Answer 2

4 comes in place of x in 3,x,5,5,9,8,15,13

Given:

Series 3,x,5,5,9,8,15,13

To Find:

What comes in place of x

Solution:

Understand the series:

Arrange in pairs

(3 , x) , ( 5 , 5) , ( 9 , 8) , ( 15 , 13)

Note the difference between numbers in pairs

3 - x  = ?

5 - 5 = 0

9 - 8  = 1

15 - 13 = 2

Notice that This difference is increasing by 1  

Hence 3 - x must be - 1

=> 3 - x = - 1

=> x = 4

Hence , 4 comes in place of x

Another way to understand the series

Break in two alternate series

3    5    9   15

  2    4     6

     2     2            

(2nd Difference is constant 2)

x        5       8      13

   1         3        5

      2           2

(Keeping 2nd Difference  constant 2)

Hence  x + 1 = 5  => x = 4

4 comes in place of x