Home / 20,980.20-31,470.30-7,129.20

Finding the Fourth Proportional to 20,980.20, 31,470.30 and 7,129.20

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Solution

The fourth proportional to 20,980.20, 31,470.30 and 7,129.20 is: 10,693.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,980.20 : 31,470.30 = 7,129.20 : x
  2. Step 2: Convert to fraction form
    20,980.20/31,470.30 = 7,129.20/x
  3. Step 3: Cross multiply
    20,980.20x = 31,470.30 × 7,129.20
  4. Step 4: Simplify right side
    20,980.20x = 224,358,062.76
  5. Step 5: Solve for x
    x = 224,358,062.76/20,980.20
  6. Step 6: Final answer
    x = 10,693.80

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.