The pressure p(in lbs/in^2) that a 160 pound persons shoe exerts on the ground when walking varies inversely with the area a(in in^2) of the sole of the shoe when the shoes have a sole area of 40 in^2 the pressure is 4 lbs/in^2 find equation that relates these variables p=

The first thing we must do for this case is to define variables.
 We have then:
 P: pressure
 A: Area of the sole of the shoe
 Since the variation is inverse, we have an equation of the form:
 
 We must find the value of k.
 For this, we use the following data:
 when the shoes have a sole area of 40 in ^ 2 The pressure is 4 lbs / in ^ 2
 Substituting values we have:
 
 From here, let's clear k:
 
 Then, the equation is:
 
 
 The equation that relates these variables is: