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Finding the Fourth Proportional to 688.08, 1,031.15 and 380.08

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Solution

The fourth proportional to 688.08, 1,031.15 and 380.08 is: 569.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.08 : 1,031.15 = 380.08 : x
  2. Step 2: Convert to fraction form
    688.08/1,031.15 = 380.08/x
  3. Step 3: Cross multiply
    688.08x = 1,031.15 × 380.08
  4. Step 4: Simplify right side
    688.08x = 391,919.49
  5. Step 5: Solve for x
    x = 391,919.49/688.08
  6. Step 6: Final answer
    x = 569.58

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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.