Ir is impossible to tell.
We are given that,
Stan earns $15 on Monday, $45 on Tuesday, Wednesday and Thursday and $60 from Monday to Friday this week.
Since, we do not have the individual earnings for each day, we are unable to plot the graph of the given relationship.
So, without graph it is impossible to state whether the relationship is linear or not.
15-1 day ✔️
45-3 day ✔️
60-5 day ❌