Question

hey

the mean of the marks scored by 50 students was found to be 39 later it was discovered that a score of 43 was misread as 23 find the correct mean.


Thank you brainly

Answer 1

Hi there!

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What is Mean?

The average of a given set of numbers is called the Arithmetic mean, or simply the mean, of the given numbers.

Mean = $\frac{Sum \: of \: observations }{Number \: of \: observations }$

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For your solution to the given question refer to the attachment.

Thanks for the question!

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Answer 2

$\underline{\bold{Solution:-}}$

Total number of students = 50

Mean of marks scored by 50 students = 39

We know that ,

$mean = \frac{Total\: marks \: of \: all \: students}{ number \: of \: students\: who\: scored \:marks} \\ \\ 39 = \frac{total \: marks \: of \: all \: students}{50} \\ \\ total \: marks \: of \: all \: students = 39 \times 50 \\ \\ total \: marks \: of \: all \: students = 1950$

Since , 43 was misread as 23.

So, we have to subtract 23 and add 43 in total marks.

New total marks = 1950-23+43

New total marks = 1970

$new \: mean \: = \frac{new \: total \: marks}{number \: of \: students} \\ \\ = \frac{1970}{50} \\ \\ = 39.4$

So, 39.4 is the new and correct mean of given marks of the 50 students.