Home / 391.78-861.75

Finding the Third Proportional to 391.78 and 861.75

Calculator

Solution

The third proportional to 391.78 and 861.75 is: 1,895.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.78 : 861.75 = 861.75 : x
  2. Step 2: Convert to fraction form
    391.78/861.75 = 861.75/x
  3. Step 3: Cross multiply
    391.78x = 861.75 × 861.75
  4. Step 4: Simplify right side
    391.78x = 742,613.06
  5. Step 5: Solve for x
    x = 742,613.06/391.78
  6. Step 6: Final answer
    x = 1,895.48

Related Problems

Find third proportional to 195.89 and 430.88
Half scale
Find third proportional to 783.56 and 1,723.50
Double scale
Find third proportional to 394 and 866
Similar ratio
Find third proportional to 587.67 and 1,292.63
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.