# ELEMENTARY STATISTICS

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50 MATH PROFESSORS WERE ASKED HOW LONG IT TAKES TO GRADE A STUDENT'S HOMEWORK ASSIGNMENT. THE MEAN GRADING TIME FOR THE SAMPLE WAS 36.2 MINUTES WITH A STANDARD DEVIATION OF 4.8 MINUTES. WHAT IS THE 99% CONFIDENCE INTERVAL FOR THE MEAN GRADING TIME OF ALL MATH PROFESSORS?

• ELEMENTARY STATISTICS -

50 MATH PROFESSORS WERE ASKED HOW LONG IT TAKES TO GRADE A STUDENT'S HOMEWORK ASSIGNMENT. THE MEAN GRADING TIME FOR THE SAMPLE WAS36.2 MINUTES WITH A STANDARD DEVIATION OF 4.8 MINUTES. WHAT IS THE 82% CONFIDENCE INTERVAL FOR THE MEAN GRADING TIME OF ALL MATH PROFESSORS?

• ELEMENTARY STATISTICS -

First, please do not use all capitals. Online it is like SHOUTING. Not only is it rude, but it is harder to understand. Thank you.

99% = mean ± 1.645 SD, .005 of scores are beyond at each end.

82% = mean ± 1.342 SD, .09 of scores are beyond at each end.

These values were found in a table table in the back of your statistics text labeled something like "areas under normal distribution."