6) (4 pts) That second point up the graph, just below 2500 km and 40 m.y. - what is its precise Y value, to the nearest 0.1 m.y.? Measure from y=0 (the X axis) vertically to the center of the dot, & from y= 0 to the 240 line at the top of the graph, both to the nearest 0.1 mm (estimate the tenths), and do a proportionality (interpolation) calculation following Geomath 5B. (We could have digitized, but we are going old-school with a ruler. I've provided other key X, Y values on the graph.) 7A (4 pts) Calculate the two slopes for the two lines on the graph, AY / AX, for A-B & B-C: AB ) BC) Geomath 5D covers calculating slopes on graphs.) 7B) (4 pts) What are your units in 7A, and what if any relationship does that have to velocity? 7C (4 pts) Use the AB slope to get the age (the Y intercept) when the distance was 0 km 7D) (5 pts) Is this a meaningful answer? Why or why not? What if anything does that answer tell us about the spreading of the Pacific? Is that logical or surprising? 12