A statistics teacher believes that the final exam grades for her elementary statistics class have a normal distribution with a mean of 82 and a standard deviation of 8
Find the score which separates the lowest 20% of the scores from the highest 80% of the scores.
I used the calculator.
\(\displaystyle invorm(.2) = -.8416 \)
\(\displaystyle 8( -.8416) + 82 = 75.26 \)
Now, the books examples(not this problem) strip the negative away after the invorm command.
So if \(\displaystyle invorm(.2) = -.8416 \) a negatve number do i use the negative or strip it away?
Find the score which separates the lowest 20% of the scores from the highest 80% of the scores.
I used the calculator.
\(\displaystyle invorm(.2) = -.8416 \)
\(\displaystyle 8( -.8416) + 82 = 75.26 \)
Now, the books examples(not this problem) strip the negative away after the invorm command.
So if \(\displaystyle invorm(.2) = -.8416 \) a negatve number do i use the negative or strip it away?