Constant of Proportionality Math Example 4
Follow the full solution, then compare it with the other examples linked below.
Example 4
mediumIf \(y = kx\) and \(y = 35\) when \(x = 7\), find \(k\) and predict \(y\) when \(x = 12\).
Solution
- 1 Find \(k\): \(k = y/x = 35/7 = 5\).
- 2 Equation: \(y = 5x\).
- 3 When \(x=12\): \(y = 5 \times 12 = 60\).
Answer
\(k = 5\); \(y = 60\) when \(x = 12\)
Find \(k = y/x\), then use \(y = kx\) to make predictions.
About Constant of Proportionality
The constant ratio between two proportional quantities: if , then is the constant of proportionality.
Learn more about Constant of Proportionality →More Constant of Proportionality Examples
Example 1 easy
A car travels 60 miles per hour. Write the equation relating distance (d) and time (t). What is the
Example 2 mediumThe table shows (x) and (y): (2, 10), (4, 20), (6, 30). Is this proportional? Find (k).
Example 3 easyApples cost $0.75 each. Write the equation for cost (C) given quantity (q). Find the cost of 8 apple