Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities and their Z scores.
Z = (score-mean)/SD
A sociology professor assigns letter grades on a test according to the following scheme.
A: Top 14% of scores
B: scores below the top 14% and above the bottom 55%
C: scores below the top 45% and above the bottom 17%
D: scores below the top 83% and above the bottom 6%
F: bottom 6 % of scores
Scores on the test are normally distributed with a mean of 78.3 and a standuard deviation of 7.3. Find the numerical limits for a B grade. Round your answers to the nearest whole number if necessary.
Can someone please help and show all work thank you so much!
1 answer