On the coordinate plane, the slope of a segment that connects the midpoints of two sides of a triangle is 1/2. the slope of the third side is 1/2. is the segment a midsegment? how do you know?

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%)