After collecting a sample of 250 elements from a population with a known standard deviation of...

After collecting a sample of 250 elements from a population with a
known standard deviation of 13.7, the mean is found to be 112.4.

a) Find a 95% confidence interval for the mean.
b) Find a 99% confidence interval for the mean.

2. Jon Jackobson, a very dedicated graduate graduate, has just completed a first
700 page version of his thesis. Jon typed the job himself and he's
interested in knowing the average number of typographical errors per page, but not
wants to read the entire document. Since he knows somethings about statistics for
Administration, Jon read 40 randomly selected pages and found that the
average typographical errors per page was 4.3 and the standard deviation of the
Sample was 1.2 errors per page.

a) Calculate the estimated standard error of the mean.
b) Calculate a 90% confidence interval for the true average number
errors per page

Expert Solution

orchestra answered 2 years ago

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