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Finding the Fourth Proportional to 669.87, 1,005 and 498.78

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Solution

The fourth proportional to 669.87, 1,005 and 498.78 is: 748.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.87 : 1,005 = 498.78 : x
  2. Step 2: Convert to fraction form
    669.87/1,005 = 498.78/x
  3. Step 3: Cross multiply
    669.87x = 1,005 × 498.78
  4. Step 4: Simplify right side
    669.87x = 501,273.90
  5. Step 5: Solve for x
    x = 501,273.90/669.87
  6. Step 6: Final answer
    x = 748.32

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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.