g = rnorm(130, m=82, sd=10)
g[g>100] = 100
g[g<1] = 1
B = boxplot(g)
divs = c(min(g), B$stats[1:4] + diff(B$stats)/2, max(g) )
####G1 = do.grades(g, cut=20, tit="GEOL 105 Exam 1")
########## replot with existing divisions:
D1 = do.grades(g, divs=divs, tit="GEOL 105 Exam 1")
jist(D1$hist, D1$grades, D1$lett)
########## or simply:
D1 = do.grades(g, divs=divs, tit="GEOL 105 Exam 1")
jist(D1)
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