Question 1012031
Due to a combination of a conformal standard and a coincidence, you just have to find the aphelion and perihelion, or the distance from the foci to the ends of the ellipse, and take the average, for this average. The two sum to be the length of the major axis, which we have as 1.16*10^8 km. The average of the two is found by dividing by two, so we divide 1.16*10^8 km for 5.08*10^8 km.