To find a good estimate for your monthly expenses on groceries, we need to convert the bi-weekly grocery expense into a monthly amount. Since there are 52 weeks in a year, that means there are 26 bi-weekly periods in a year.
The bi-weekly grocery cost is $113.50. To find the monthly cost, we can multiply this amount by 2 (for two bi-weekly periods in a month):
\[ \text{Monthly Groceries Expense} = 113.50 \times 2 = 227.00 \]
So, a good estimate for your monthly expenses on groceries is $227.00.