Question

the mean of 10 observations was calculated as 40.it was detected on rechecking that the value of 45 was wrongly copied is 15.find the correct mean

Answer 1

Let the sum of total observations be x
 by mean formula,

Sum of total observations / total no. of observations = mean
x/10=40
x = 40 x 10
x=400

by given condition
x = 400-15+45= 430 
put value of x in mean formula

430/10=43
the correct mean is 43

Answer 2

Answer:

43

Step-by-step explanation:

Let the sum of total observations be x

by mean formula,

Sum of total observations / total no. of observations = mean

x/10=40

x = 40 x 10

x=400

by given condition

x = 400-15+45= 430  

put value of x in mean formula

430/10=43

the correct mean is 43