The data gives the average percentage memory retention measured against passing time (minutes). The measurements were taken five times during the first hour after subjects memorized a list of...

The data gives the average percentage memory retention measured against passing time (minutes). The measurements were taken five times during the first hour after subjects memorized a list of disconnected items, and then at various times up to a week later. Plot the data (after a suitable transformation if necessary) and investigate the relationship between retention and time using a suitable regression model.