Word problem for stat! need assistance please

[paris567]

Hello fellow people reading this....im working on stats in math currently. Im struggling with this question and i know the basic of statistics but I'm not sure how to start this question.
"The marks on a Biology exam at a University were found to have a mean of 70 with a
standard deviation of 14. A professor thought the exam was too difficult, so he decided to
adjust the original marks by raising the mean to 75%, while reducing the standard deviation to 8
and leaving the z-scores unchanged. What would the new mark to the nearest tenth be for a
student who received an original mark of 45%?"

 

[tkhunny]

Philosophy Day:

Why not calculate the Z-score from the original values and then see what it takes to do the same with the altered values?

(45-70)/14 = What
(Who-75)/8 = the Same "What"

What's the point of tinkering with the distribution if the Z-scores don't change?

(100-70)/14 = 2.143 (98.4th percentile)
(100-75)/8 = 3.125 (99.9th percentile) <== Changing Z-Scores
A score of 100% looks cooler, now, but it can't increase. Is that fair?
By tinkering with the distribution, this top student went from from the top 16 of 1000 students to the top 1 of 1000 students. What happened to the other 15 top students?

Or (92.144 - 75)/8 = 2.143 (98.4th percentile) <== Not changing Z-Scores
So this student scored 100, but is credited only with 92.144? How does that make sense?

(45-70)/14 = -1.786 (3.7th percentile)
(60.712-75)/8 = -1.786 (3.7th percentile)

Anyway, this is why we strive to create good exams. It's just a mess when a good look at the total results just doesn't make any sense. Adjustments are for individuals. Guilt is for the class as a whole. The sum of the parts is not always the desired total.

My views. I welcome others'.