Question is lengthy so I've attached the screenshot. Can you help? It's probability.

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Answer 1 · 2018-04-19T03:15:02

#84%#

.

Let's assign a few parameters:

#z=# total number of students.

#x=# the number of students that got a score of #80/100# or higher on midterm #1#.

#y=# the number of students that got a score of #80/100# or higher on midterm #2#.

Now, we can say:

#x/z=0.25, :. x=0.25z#

#y/z=0.21, :. y=0.21z#

The percentage of the students who had a score of #80/100# or higher on midterm #1# also got a score of #80/100# or higher on midterm #2# is:

#y/x=(0.21z)/(0.25z)=21/25=84/100=84%#

#84%# of the students that scored #80/100# on midterm #1# also scored #80/100# or higher on midterm #2#.