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Finding the Fourth Proportional to 688.17, 1,031.49 and 379.86

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Solution

The fourth proportional to 688.17, 1,031.49 and 379.86 is: 569.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.17 : 1,031.49 = 379.86 : x
  2. Step 2: Convert to fraction form
    688.17/1,031.49 = 379.86/x
  3. Step 3: Cross multiply
    688.17x = 1,031.49 × 379.86
  4. Step 4: Simplify right side
    688.17x = 391,821.79
  5. Step 5: Solve for x
    x = 391,821.79/688.17
  6. Step 6: Final answer
    x = 569.37

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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.