At a local music store CDs cost 11.99including tax is the number of CDs purchased proportional to the cost of the CDs

n + .08n = 11.99 tax = 8%

1.08 n = 11.99

11.10=n tax is .89

lets say the is 6%

11.31 = n tax is .68

they are proportional. The proportion is the tax.

try dividing the tax by the n in each case to see that the answer is the sales tax we used.

At a local music store CDs cost 11.99including tax is the number of CDs purchased proportional to the cost of the CDs What is the cost of 3 CDs

No, the number of CDs purchased is not necessarily proportional to the cost of the CDs. Proportional means that if one quantity increases or decreases by a certain factor, the other quantity also increases or decreases by the same factor.

In this case, even though the cost of the CDs is fixed at $11.99 including tax, the number of CDs purchased can vary depending on individual preferences, budget, and other factors. Some people may choose to purchase multiple CDs, while others may only buy one or none at all. Therefore, the number of CDs purchased is not directly or necessarily proportional to the cost of the CDs.

To determine if the number of CDs purchased is proportional to the cost of the CDs at a local music store, you would need to gather data on the number of CDs purchased and their corresponding costs.

1. Collect Data: Keep track of the number of CDs purchased and their costs over a period of time. For example:

- Purchase 1: 3 CDs for $35.97 (3 CDs * $11.99)
- Purchase 2: 5 CDs for $59.95 (5 CDs * $11.99)
- Purchase 3: 2 CDs for $23.98 (2 CDs * $11.99)
- and so on...

2. Calculate the proportion: Once you have collected a sufficient amount of data, you can calculate the proportion between the number of CDs and their cost. This can be done by dividing the cost of CDs by the number of CDs purchased for each transaction.

- Purchase 1: $11.99 per CD ($35.97 / 3 CDs)
- Purchase 2: $11.99 per CD ($59.95 / 5 CDs)
- Purchase 3: $11.99 per CD ($23.98 / 2 CDs)
- and so on...

3. Analyze the results: If the proportion between the number of CDs and their cost remains consistent over multiple transactions (i.e., all the calculated proportions are the same or very similar), then it indicates that the number of CDs purchased is proportional to the cost of the CDs.

Note: Keep in mind that some variations in the calculated proportions may occur due to factors like discounts, promotions, or rounding errors. However, if the overall pattern indicates a consistent proportionality, then it suggests a linear relationship between the number of CDs and their cost.