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Finding the Fourth Proportional to 688.20, 1,031.34 and 456.42

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Solution

The fourth proportional to 688.20, 1,031.34 and 456.42 is: 683.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.20 : 1,031.34 = 456.42 : x
  2. Step 2: Convert to fraction form
    688.20/1,031.34 = 456.42/x
  3. Step 3: Cross multiply
    688.20x = 1,031.34 × 456.42
  4. Step 4: Simplify right side
    688.20x = 470,724.20
  5. Step 5: Solve for x
    x = 470,724.20/688.20
  6. Step 6: Final answer
    x = 683.99

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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.