Question

Mean of 20 observations is 15.5. Later it was found that 24 was misread as 42. Find the correct mean.

Answer 1

Answer:

Correct mean:14.6

Step-by-step explanation:

We know that

$mean = \frac{sum \: of \: all \: observation}{total \: observation}$

Mean of 20 observations is 15.5

so

sum of all observation = 20×15.5

=310

Later it was found that 24 was misread as 42.

sum of observation after correction

= 310-42+24

= 292

$new \: mean = \frac{392}{20} \\ \\ =14.6$

Hope it helps you.

Answer 2

Correct mean is 14.6.

Step-by-step explanation:

Since we have given that

Number of observations = 20

Mean = 15.5

So, it becomes,

$\dfrac{\sum x}{n}=\bar{x}\\\\\dfrac{\sum x}{20}=15.5\\\\\sum x=15.5\times 20\\\\\sum x=310$

Since it was found that 24 was misread as 42

So, it becomes,

$\sum x-42+24=310-42+24=292$

So, Correct mean would be

$\dfrac{292}{20}=14.6$

Hence, correct mean is 14.6.

# learn more:

The mean of 8 observations was found to be 20. Later it was detected that one of the observations was

misread as 62. What is the correct observation, if the correct mean is 15.5 ?

https://brainly.in/question/10351194