The sales tax for an item was $16.50 and it cost $330 before tax.Find the sales tax rate. Write your answer as a percentage.

1. ### Break Down the Problem

To find the sales tax rate, we need to determine the relationship between the sales tax amount, the cost before tax, and the sales tax rate. The formula to relate these quantities is: $\text{Sales Tax} = \text{Cost before tax} \times \text{Sales Tax Rate}$

2. ### Relevant Concepts

Let $\text{Sales Tax Rate} = r$. From the problem:

• Sales Tax = $16.50
• Cost before Tax = $330

The relationship can be expressed as: $16.50 = 330 \times r$

3. ### Analysis and Detail

To find the sales tax rate $r$, we rearrange the formula: $r = \frac{\text{Sales Tax}}{\text{Cost before Tax}} = \frac{16.50}{330}$

Now we will perform the calculation: $r = \frac{16.50}{330} = 0.05$

4. ### Verify and Summarize

To convert $r$ into a percentage, we multiply by 100: $r = 0.05 \times 100 = 5\%$

Final Answer

The sales tax rate is $5\%$.