Home / 420.19-856.69

Finding the Third Proportional to 420.19 and 856.69

Calculator

Solution

The third proportional to 420.19 and 856.69 is: 1,746.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 856.69 = 856.69 : x
  2. Step 2: Convert to fraction form
    420.19/856.69 = 856.69/x
  3. Step 3: Cross multiply
    420.19x = 856.69 × 856.69
  4. Step 4: Simplify right side
    420.19x = 733,913.47
  5. Step 5: Solve for x
    x = 733,913.47/420.19
  6. Step 6: Final answer
    x = 1,746.63

Related Problems

Find third proportional to 210.09 and 428.34
Half scale
Find third proportional to 840.38 and 1,713.38
Double scale
Find third proportional to 422 and 861
Similar ratio
Find third proportional to 630.28 and 1,285.03
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.04) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.