A man is camping on an island 1 space k m from the nearest point on the shoreline. He wants to go to the store which is 4 space k m down the shoreline. The man can paddle his canoe at 7 space k m divided by h and he can jog at 8 space k m divided by h. Find x, the horizontal distance along the shore, across from where his island is, that the man should aim to land his canoe in order to reach the store in the least time.