Home / 355-515

Finding the Third Proportional to 355 and 515

Calculator

Solution

The third proportional to 355 and 515 is: 747.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    355 : 515 = 515 : x
  2. Step 2: Convert to fraction form
    355/515 = 515/x
  3. Step 3: Cross multiply
    355x = 515 × 515
  4. Step 4: Simplify right side
    355x = 265,225
  5. Step 5: Solve for x
    x = 265,225/355
  6. Step 6: Final answer
    x = 747.11

Related Problems

Find third proportional to 177.50 and 257.50
Half scale
Find third proportional to 710 and 1,030
Double scale
Find third proportional to 357 and 518
Similar ratio
Find third proportional to 532.50 and 772.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.45) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.