434 Example 7.1. The table gives the distance in nautical miles of the visible horizon for the given heights in feet above the earth's surface : x = height's OU 100 150 200 250 300 350 400 y = distance : 10.63 13.03 15.04 16.81 18.42 19.90 21.27 Find the values of y when (i) x = 218 ft (it) x = 410