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Finding the Fourth Proportional to 557.87, 769.86 and 309.21

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Solution

The fourth proportional to 557.87, 769.86 and 309.21 is: 426.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    557.87 : 769.86 = 309.21 : x
  2. Step 2: Convert to fraction form
    557.87/769.86 = 309.21/x
  3. Step 3: Cross multiply
    557.87x = 769.86 × 309.21
  4. Step 4: Simplify right side
    557.87x = 238,043.02
  5. Step 5: Solve for x
    x = 238,043.02/557.87
  6. Step 6: Final answer
    x = 426.70

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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.