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Finding the Fourth Proportional to 680, 938.40 and 404

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Solution

The fourth proportional to 680, 938.40 and 404 is: 557.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    680 : 938.40 = 404 : x
  2. Step 2: Convert to fraction form
    680/938.40 = 404/x
  3. Step 3: Cross multiply
    680x = 938.40 × 404
  4. Step 4: Simplify right side
    680x = 379,113.60
  5. Step 5: Solve for x
    x = 379,113.60/680
  6. Step 6: Final answer
    x = 557.52

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.