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Finding the Fourth Proportional to 683.80, 1,025.70 and 392.20

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Solution

The fourth proportional to 683.80, 1,025.70 and 392.20 is: 588.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    683.80 : 1,025.70 = 392.20 : x
  2. Step 2: Convert to fraction form
    683.80/1,025.70 = 392.20/x
  3. Step 3: Cross multiply
    683.80x = 1,025.70 × 392.20
  4. Step 4: Simplify right side
    683.80x = 402,279.54
  5. Step 5: Solve for x
    x = 402,279.54/683.80
  6. Step 6: Final answer
    x = 588.30

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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.