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Finding the Fourth Proportional to 666.60, 999.90 and 447.90

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Solution

The fourth proportional to 666.60, 999.90 and 447.90 is: 671.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.60 : 999.90 = 447.90 : x
  2. Step 2: Convert to fraction form
    666.60/999.90 = 447.90/x
  3. Step 3: Cross multiply
    666.60x = 999.90 × 447.90
  4. Step 4: Simplify right side
    666.60x = 447,855.21
  5. Step 5: Solve for x
    x = 447,855.21/666.60
  6. Step 6: Final answer
    x = 671.85

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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.