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Finding the Fourth Proportional to 687.75, 1,031.38 and 440.59

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Solution

The fourth proportional to 687.75, 1,031.38 and 440.59 is: 660.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.75 : 1,031.38 = 440.59 : x
  2. Step 2: Convert to fraction form
    687.75/1,031.38 = 440.59/x
  3. Step 3: Cross multiply
    687.75x = 1,031.38 × 440.59
  4. Step 4: Simplify right side
    687.75x = 454,415.71
  5. Step 5: Solve for x
    x = 454,415.71/687.75
  6. Step 6: Final answer
    x = 660.73

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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.