Home / 513-621

Finding the Third Proportional to 513 and 621

Calculator

Solution

The third proportional to 513 and 621 is: 751.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    513 : 621 = 621 : x
  2. Step 2: Convert to fraction form
    513/621 = 621/x
  3. Step 3: Cross multiply
    513x = 621 × 621
  4. Step 4: Simplify right side
    513x = 385,641
  5. Step 5: Solve for x
    x = 385,641/513
  6. Step 6: Final answer
    x = 751.74

Related Problems

Find third proportional to 256.50 and 310.50
Half scale
Find third proportional to 1,026 and 1,242
Double scale
Find third proportional to 515 and 623
Similar ratio
Find third proportional to 769.50 and 931.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.21) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.