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Finding the Fourth Proportional to 687.88, 1,030.60 and 379.68

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Solution

The fourth proportional to 687.88, 1,030.60 and 379.68 is: 568.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.88 : 1,030.60 = 379.68 : x
  2. Step 2: Convert to fraction form
    687.88/1,030.60 = 379.68/x
  3. Step 3: Cross multiply
    687.88x = 1,030.60 × 379.68
  4. Step 4: Simplify right side
    687.88x = 391,298.21
  5. Step 5: Solve for x
    x = 391,298.21/687.88
  6. Step 6: Final answer
    x = 568.85

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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.