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Finding the Fourth Proportional to 688.91, 1,031.70 and 414.38

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Solution

The fourth proportional to 688.91, 1,031.70 and 414.38 is: 620.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.91 : 1,031.70 = 414.38 : x
  2. Step 2: Convert to fraction form
    688.91/1,031.70 = 414.38/x
  3. Step 3: Cross multiply
    688.91x = 1,031.70 × 414.38
  4. Step 4: Simplify right side
    688.91x = 427,519.98
  5. Step 5: Solve for x
    x = 427,519.98/688.91
  6. Step 6: Final answer
    x = 620.58

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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.