The slope {s} of a beach is related to the average diameter {d} (in millimeters) of the sand particles on the beach by this equation: s = 0.159+0.118logd use your graphing calculator to estimate the average diameter, d, of the sand particles for a beach whose slope, s, is 0.2.

For this case we have the following equation:
 S = 0.159 + 0.118logD
 Substituting S = 0.2 we have:
 0.2 = 0.159 + 0.118logD
 From here, we clear the value of D.
 We have then:
 0.2 - 0.159 = 0.118logD
 logD = (0.2 - 0.159) / (0.118)
 logD = 0.347457627
 10 ^ (logD) = 10 ^ 0.347457627
 D = 10 ^ (0.347457627)
 D = 2.23 mm
 
 The average diameter, D, of the sand particles for a beach is:
 D = 2.23 mm