4. (10 pts) In a psychological experiment, participants were shown a series of images of common household items and asked to recall them each minute after the experiment. The percentage of
participants who recalled the images after t minutes is given by the equation R(t) = 85 - 30 In t.
a. What percentage of participants recalled the images after 1 minute? Round to 2 decimal
places.
b. Calculate R'(3) and explain its meaning in a complete sentence.