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Cell["Project - GPA ", "Title"],

Cell["\<\
In the academic year 2005-2006, 6286 grades were awarded in all math courses \
at CSULA (at least the ones that are graded ABCDF). For example, 1474 As were \
awarded - not necessarily to 1474 different students, since an individual \
student may get As in several courses over a year. \
\>", "Text"],

Cell["\<\
Grade\tCount GPA
A \t1474\t  4.0
A- \t249\t  3.7
B \t1177\t  3.0
B+ \t339\t  3.3
B- \t236\t  2.7
C \t1743\t  2.0
C+ \t300\t  2.3
C- \t81\t  1.7
D \t329\t  1.0
D+ \t25\t  1.3
D- \t20\t  0.7
F \t313\t  0.0
\t\t
Total   6286\t\
\>", "Text"],

Cell["\<\
For the purpose of calculating the grade point average (GPA) for students (or \
classes, or courses, etc.) each letter grade corresponds to a number between \
0 and 4 as shown in the table. The GPA for the entire data set is calculated \
as follows:\
\>", "Text"],

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Cell["\<\
Hence the average grade over the entire academic year was appoximately B-.\
\>", "Text"],

Cell["\<\
It happens that, in this academic year, some changes were made to the way \
that calculus was taught that seemed to increase the gpa in those courses. \
For example, in one class of 20 students the average GPA was 3.0.  It is not \
clear if this is due to the changes made to the course, or whether this is \
just a coincidence - after all, maybe this class had, by luck, some of the \
higher scoring students in it.  To give some idea of how much variation in \
the GPA can be explained by random causes, the following calculation can be \
done:

Select 20 grades at random from the 6286 listed in the table, and then \
calculate the average gpa for this \"random\" class of 20 students. This \
average gpa will presumably be near 2.67, but may be a bit below or above.  \
Repeat this process several thousand times to get a distribution of average \
gpas for this class size. Calculate the standard deviation. 

If the standard deviation is much less than 0.3 (3.0-2.7), then one would \
have reason to believe that the 3.0 gpa obtained in that single calculus \
class may not be due randomness.\
\>", "Text"],

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Cell[TextData[{
 "Your project is to implement the calculation described above using ",
 StyleBox["Mathematica",
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 ". It would also be useful to have a graph of the distribution of gpas for \
this class size."
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