Question

The mean of 26, 14, x, 25, 15, 13, 27, 18 is 18.75. Find the value of x.
4. The mean of six numbers is 30. If one number is excluded, the mean is 29. Find the excluded nurra
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Answer 1

Step-by-step explanation:

1) 26 + 14 + x + 25 + 15 + 13 + 27 + 18÷ 8 = 18.75

138 + x ÷ 8 = 18.75

138 + x = 150

x = 150 - 138 = 12

2) x÷6 = 30 Therefore x =180

x ÷ 5 = 29 Here x = 145

so the excluded number is 180 - 145 = 35

Answer 2

Answer:

The value of x is 12.

The excluded number is 35

Step-by-step explanation:

Given that the mean of 26, 14, x, 25, 15, 13, 27, 18 is 18.75

=> $\frac{26+14+ x+ 25+ 15+ 13+ 27+ 18 }{8}$ = 18.75

=>  $\frac{138+x}{8}$ = 18.75

=> 138 + x = 150

=> x = 150 - 138

=> x = 12

Therefore, the value of x is 12.

Given that the mean of 6 numbers = 30

Mean of 5 numbers = 29

Let the numbers be a, b, c, d, e, f

Therefore, according to the conditions above,

=> $\frac{a+b+c+d+e+f}{6}$ = 30

=> a + b + c + d + e + f = 180              --(i)

and  $\frac{a+b+c+d+e}{5}$ = 29

=>  a + b + c + d + e  = 145                --(ii)

Substituting the value of a + b + c + d + e from equation (ii) to equation (i)

=>  145 + f = 180

=> f = 180 - 145

=> f = 35

Therefore, the excluded number is 35