Question

The mean of 9 observations is 35 .lately it is found at the observation 8 was misread as 18 the correct mean of the observation will be what

Answer 1

Answer:

33.8

Step-by-step explanation:

sum of observation = 35*9= 315

now sum of 8 observation excluding 18 is 315 - 18 = 297

new mean = now sum of 8 observation + the observation 8/9

297 + 8/9

305/9

= 33.8

if it helps comment me

Answer 2

Answer:

Let the observations be = $\tt{x_{1} , x_{2} , ... x_{9}}$

Mean = $\tt{\frac{Sum\: of\: observations}{No.\: of\: observations}}$

Mean = $\tt{\frac{x_{1} + x_{2} + x_{3} + ... x_{9} }{9}}$ = 35

=> $\tt{x_{1} + x_{2} + ... x_{9} = 315 }$

=> $\tt{x_{1} + x_{2} + ... x_{8} + 18 = 315}$

=> $\tt{x_{1} + x_{2} + ... x_{8} = 297}$

Mean:

=> $\tt{\frac{x_{1} + x_{2} + ... x_{8} + 8}{9}}$

=> $\tt{\frac{297 + 8}{9}}$

=> 33.89

Thus, mean changes to 33.89

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