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Finding the Fourth Proportional to 687.70, 1,031.28 and 254.62

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Solution

The fourth proportional to 687.70, 1,031.28 and 254.62 is: 381.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.70 : 1,031.28 = 254.62 : x
  2. Step 2: Convert to fraction form
    687.70/1,031.28 = 254.62/x
  3. Step 3: Cross multiply
    687.70x = 1,031.28 × 254.62
  4. Step 4: Simplify right side
    687.70x = 262,584.51
  5. Step 5: Solve for x
    x = 262,584.51/687.70
  6. Step 6: Final answer
    x = 381.83

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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.