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Finding the Fourth Proportional to 557.20, 768.90 and 308.51

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Solution

The fourth proportional to 557.20, 768.90 and 308.51 is: 425.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    557.20 : 768.90 = 308.51 : x
  2. Step 2: Convert to fraction form
    557.20/768.90 = 308.51/x
  3. Step 3: Cross multiply
    557.20x = 768.90 × 308.51
  4. Step 4: Simplify right side
    557.20x = 237,209.49
  5. Step 5: Solve for x
    x = 237,209.49/557.20
  6. Step 6: Final answer
    x = 425.72

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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.