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Finding the Fourth Proportional to 669.86, 1,003.68 and 486.39

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Solution

The fourth proportional to 669.86, 1,003.68 and 486.39 is: 728.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.86 : 1,003.68 = 486.39 : x
  2. Step 2: Convert to fraction form
    669.86/1,003.68 = 486.39/x
  3. Step 3: Cross multiply
    669.86x = 1,003.68 × 486.39
  4. Step 4: Simplify right side
    669.86x = 488,179.92
  5. Step 5: Solve for x
    x = 488,179.92/669.86
  6. Step 6: Final answer
    x = 728.78

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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.