Home / 390.56-699.75

Finding the Third Proportional to 390.56 and 699.75

Calculator

Solution

The third proportional to 390.56 and 699.75 is: 1,253.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.56 : 699.75 = 699.75 : x
  2. Step 2: Convert to fraction form
    390.56/699.75 = 699.75/x
  3. Step 3: Cross multiply
    390.56x = 699.75 × 699.75
  4. Step 4: Simplify right side
    390.56x = 489,650.06
  5. Step 5: Solve for x
    x = 489,650.06/390.56
  6. Step 6: Final answer
    x = 1,253.70

Related Problems

Find third proportional to 195.28 and 349.88
Half scale
Find third proportional to 781.13 and 1,399.50
Double scale
Find third proportional to 393 and 703
Similar ratio
Find third proportional to 585.84 and 1,049.63
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.79) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.