Final answer:
In inverse variation, when two variables are inversely proportional, their product remains constant. To solve this problem, use the inverse variation equation and the given values to find the constant. Then, substitute the constant and the new value of the first variable into the equation to find the second variable.
Step-by-step explanation:
In inverse variation, when two variables are inversely proportional, their product remains constant. To solve this problem, we can use the inverse variation equation:
p * q = k
where p is the first variable, q is the second variable, and k is the constant.
Given that p is 21 when q is 23, we can substitute these values into the equation:
21 * 23 = k
k = 483
Now we can use the constant k to solve for q when p is 7:
7 * q = 483
q = 483 / 7
q ≈ 69.