To calculate how much Naomi saved after a year by not joining the fan club, we need to multiply the weekly cost by the number of weeks in a year.
- The weekly cost of the fan club is $7.50.
- There are 52 weeks in a year.
Now, we can calculate the total cost for a year:
\[ \text{Total cost for a year} = 7.50 \times 52 = 390 \]
So, by not joining the fan club, Naomi saved $390 after a year.