10. There are 20 students in a Grade 8 class.
Eighteen students wrote a Social Studies test.
Here are their marks: 75, 56, 83, 61, 91, 42, 57, 56, 60, 87,
32, 42, 57, 67, 89, 43, 49,81
Two students who were absent wrote the test the next day.
The mean mark for the 20 students was 63.
The range was 63.
a) What are the median mark and the mode mark
for the 18 students?
b) What are possible marks for the two students
who wrote the test late?
c) Suppose the teacher gives each student 3 extra
marks. How do the mean, median, mode, and range change?