Home / 7-18

Finding the Third Proportional to 7 and 18

Calculator

Solution

The third proportional to 7 and 18 is: 46.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    7 : 18 = 18 : x
  2. Step 2: Convert to fraction form
    7/18 = 18/x
  3. Step 3: Cross multiply
    7x = 18 × 18
  4. Step 4: Simplify right side
    7x = 324
  5. Step 5: Solve for x
    x = 324/7
  6. Step 6: Final answer
    x = 46.29

Related Problems

Find third proportional to 3.50 and 9
Half scale
Find third proportional to 14 and 36
Double scale
Find third proportional to 9 and 23
Similar ratio
Find third proportional to 10.50 and 27
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.