Question

If the average Of nine number is21.and 10number is 31 .what is the all 10number average

Answer 1

Step-by-step explanation:

Let the sum of all observation to be x

Number of observation = 9

Average = 21

.'. Average =sum of all observation / Number of

observation

21 = x/9

x = 21× 9

= 189

Hence, sum of all observation = 189

So, sum of all observation = 189+31 = 220

Number of observation = 9+1 =10

Thus, new average = 220/10

= 22

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