Question

If the mean of 8, 10, 7, X + 2 and 6 is 9, find the value of x.​

Answer 1

Answer:

mean=sum of all observations÷ number of all observations

Step-by-step explanation:

8+10+7+x+2+6

÷5=9

x+33÷5=9

x+33=9×5

x+33=45

x=45-33

x=12

Answer 2

Answer:

x = 12

x + 2 = 14

Step-by-step explanation:

Given Observations :

• 8 , 10 , 7 , x + 2 , 6

• The mean of observations = 9

To find Mean :

${\underline{\boxed{\bf{mean \: = \frac{total \: observations}{no.of \: observations} }}}}$

• Total observations = 8+10+7+x+2+6 = 31+x+2

• No. of observations = 5

Solution :

$\to\sf \frac{8 + 10 + 7 + x + 2 + 6}{5} = 9 \\ \\ \to\sf \frac{31 + x + 2}{5} = 9 \\ \\ \to\sf \: \frac{33 + x}{5} = 9 \\ \\ \sf\to33 + x = 9 \times 5 \\ \\ \to\sf \: 33 + x = 45 \\ \\ \to\sf \: x = 45 - 33 \\ \\ \to\bf \: x = 12$

So , x = 12

$= \sf \: x + 2 = 12 + 2 \\ = \sf14$

Hence, the observations( series ) are :

8 , 10 , 7 , 14 , 6

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