The function P(x) = 85 - 35 log 2x models the percentage, P(x), of students who could recall the important features of a classroom lecture as a function of time, where x represents the number of days that have elapsed since the lecture was given. The figure shows the graph of the function. After how many days do only two-fifths of the
students recall the important features of the classroom lecture? (Let P(x) = 40 and solve for x) Locate the point on the graph that conveys this information