Question

A sample of 1000 students whose mean weight is 119 lbs (pounds) from a school in Tamil Nadu State was taken and their average weight was found to be 120 lbs with a standard deviation of 30 lbs. Calculate the standard error of the mean

Answer 1

Given n = 1000

`bar(x)` = 119 lbs  ......(pounds)

Since σ is unknown

So we consider `barsigma` = s and µ = 120 lbs

S.E = `barsigma/sqrt("n")`

= `"s"/sqrt("n")`

= `30/sqrt(1000)`

= `30/31.623`

= 0.9487

Therefore the standard error for the average weight of large group of students of 120 lbs is 0.9487