What is the scale factor of the dilation shown?

Ineed with number 17 i don’t get it at alll

Explain how you could use the interactive table to tell if sets of points are on the same line. math 8

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)