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Finding the Fourth Proportional to 687.72, 1,031.33 and 297.70

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Solution

The fourth proportional to 687.72, 1,031.33 and 297.70 is: 446.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.72 : 1,031.33 = 297.70 : x
  2. Step 2: Convert to fraction form
    687.72/1,031.33 = 297.70/x
  3. Step 3: Cross multiply
    687.72x = 1,031.33 × 297.70
  4. Step 4: Simplify right side
    687.72x = 307,026.94
  5. Step 5: Solve for x
    x = 307,026.94/687.72
  6. Step 6: Final answer
    x = 446.45

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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.