Home / 485-518

Finding the Third Proportional to 485 and 518

Calculator

Solution

The third proportional to 485 and 518 is: 553.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    485 : 518 = 518 : x
  2. Step 2: Convert to fraction form
    485/518 = 518/x
  3. Step 3: Cross multiply
    485x = 518 × 518
  4. Step 4: Simplify right side
    485x = 268,324
  5. Step 5: Solve for x
    x = 268,324/485
  6. Step 6: Final answer
    x = 553.25

Related Problems

Find third proportional to 242.50 and 259
Half scale
Find third proportional to 970 and 1,036
Double scale
Find third proportional to 487 and 520
Similar ratio
Find third proportional to 727.50 and 777
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.07) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.