Explanation:
To find the constant of proportionality, we can set up a ratio between the number of T-shirts and their respective prices.
Let's denote the number of T-shirts as 'n' and the price as 'p'.
Given that the store offers $180 for 6 T-shirts and $270 for 9 T-shirts, we can set up the following ratios:
180/6 = p/n
270/9 = p/n
We can simplify these ratios by dividing both the numerator and denominator by their greatest common divisor (GCD). The GCD of 180 and 6 is 6, and the GCD of 270 and 9 is also 9. Simplifying the ratios, we get:
30 = p/n
30 = p/n
Since the ratios are equal, we can write the equation of proportionality as:
p/n = 30
The constant of proportionality is 30.
To find the price of 15 T-shirts, we can use the equation of proportionality:
p/n = 30
Substituting the values, we get:
p/15 = 30
Solving for 'p', we find:
p = 30 * 15 = 450
Therefore, the price of 15 T-shirts will be $450.
If the price of a T-shirt changed to $43, we can use the equation of proportionality to find the price of 7 T-shirts:
p/n = 30
Substituting the values, we get:
43/n = 30
Solving for 'n', we find:
n = 43 / 30 * 7 = 10.77 (rounded to two decimal places)
Therefore, the price of 7 T-shirts, when each T-shirt costs $43, will be approximately $10.77.