Question

Question #e37a2

Answer 1

a) C or above: `color(white)("XXXX")66 1/3%`

b) C or 550-650: `color(white)("XXX")75 1/3%`

c) score <550 or >650: `40%`

c) A or B or >650: `color(white)("XXX")37%`

Explanation:

a) grade C or above
From the table:
#color(white)("XXX"){: ("grade of C",color(white)("XX"),115), ("grade of A or B",,underline(color(white)("x")84)), (,"total=",199) :}#
`199` out of a total of `300` students got C or above

`199/300=66 1/3%`
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b) grade C or score 550-650
From the table:
#color(white)("XXX"){: ("grade of C",,115), ("grade of C and score 550-650",,underline(color(white)(1)69)), ("grade of C but not score 550-650",,color(white)(1)46), ("score 550-650",,underline(180)), (,"grade C or score 550-650",226) :}#
The trick here is to make sure you do not count the students who got a grade of C and a score of 550-650 twice.
#226/300 = 75 1/3%
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c) Score below 550 or above 650
Note that in this case the subgroups are mutually exclusive (nobody can be both below 550 and above 650)
From the table:
#color(white)("XXX"){: ("score below 550",,color(white)(1)65), ("score above 650",,underline(color(white)(1)55)), (,"total=",120) :}#
`120` students out of `300` got a score below 550 or above 650

`120/300=40%`
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d) Grade of A or B or score above 650
Again we need to be careful not to double count the students who got both an A or B and a score above 650.
(I will use a alternative version than I used for b).
From the table:
#color(white)("XXX"){: ("grade of A or B",,color(white)(1)84), ("score above 55",,underline(color(white)(1)55)), (,"total=",139), ("grade above A or B and score above 650",,underline(color(white)(1)28)), (color(white)("XXX")"grade of A or B and score above 650",,111) :}#
`111` students out of `300` got a grad of A or B and a score greater than 650.

`111/300= 37%`

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