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Finding the Fourth Proportional to 686.98, 1,031.07 and 649.31

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Solution

The fourth proportional to 686.98, 1,031.07 and 649.31 is: 974.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.98 : 1,031.07 = 649.31 : x
  2. Step 2: Convert to fraction form
    686.98/1,031.07 = 649.31/x
  3. Step 3: Cross multiply
    686.98x = 1,031.07 × 649.31
  4. Step 4: Simplify right side
    686.98x = 669,484.06
  5. Step 5: Solve for x
    x = 669,484.06/686.98
  6. Step 6: Final answer
    x = 974.54

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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.