In an examination, the mean of marks scored by a class of 30 students was calculated as 58.5 Later on, it was detected that the marks of one student was wrongly copied as 57 instead of 75. Find the correct mean.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
`”Mean of marks” = (“incorrect marks of 30 students”)/(30)`
`therefore” “58.5 = (“incorrect sum of marks”)/(30)`
` rArr ” “”Incorrect sum of marks” = 58.5 xx 30 = 1755`
As marks of one student was wrongly copied as 57 instead of 75, correct sum of marks
`=”Wrong sum – Wrong value + Correct value”`
`=1755 – 57 + 75 = 1773`
`therefore” “”Correct mean ” = (1773)/(30) = 59.1`