14.3
step-by-step explanation:
add all the numbers together.
9 + 12 + 15 + 16 + 17 + 17 = 86
now, divide 86 by how many numbers we have: 6.
86 / 6 = 14.3
make sure you have version 2.50
try looking in the very back of the book : )
you can download it here
25/6
you multiply 4 by the denominator (4*6=24) and add it to the numerator which makes it 25/6.