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Finding the Fourth Proportional to 666.57, 999.80 and 315.09

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Solution

The fourth proportional to 666.57, 999.80 and 315.09 is: 472.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.57 : 999.80 = 315.09 : x
  2. Step 2: Convert to fraction form
    666.57/999.80 = 315.09/x
  3. Step 3: Cross multiply
    666.57x = 999.80 × 315.09
  4. Step 4: Simplify right side
    666.57x = 315,025.41
  5. Step 5: Solve for x
    x = 315,025.41/666.57
  6. Step 6: Final answer
    x = 472.61

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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.