The percent y of U. S. college freshmen who identified computer science as their probable field of study from 2001 to 2005 decreased in a pattern that was approximately parabolic. The least squares regression parabola y = at² + bt + c for the data is found by solving the system
5c + 15b + 55a = 9.7
15c + 55b + 225a = 23.9
55c +225b + 979a = 77.3
Let t represent the year, with t=1 corresponding to 2001.​

Anna is constructing a line segment that is congruent to another segment ab. for the construction, which tool should be used to mesure segment ab

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

The school track has eight lanes. each lane is 1.25 meters wide. the arc at each end of the track is 180. the distance of the home straight and the radii for the arcs in the 1st 4 lanes are given. s=85m r1=36.5m r2=37.75m r3=39m r4=40.25m part one: find the radii of lanes 5 through 8 of the track. show your work. part two: if max ran around lane one, how far did he run? show your work and explain your solution. part three: max wants to run a total of three laps around the track, choose two additional lanes (2-8) for him to run and find the distance around those two lanes. show your work and round to the hundredths. part 4: based on your lane choices in part three, what was the total distance max ran in the three laps around the track?