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Finding the Fourth Proportional to 666.15, 999.21 and 203.91

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Solution

The fourth proportional to 666.15, 999.21 and 203.91 is: 305.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.15 : 999.21 = 203.91 : x
  2. Step 2: Convert to fraction form
    666.15/999.21 = 203.91/x
  3. Step 3: Cross multiply
    666.15x = 999.21 × 203.91
  4. Step 4: Simplify right side
    666.15x = 203,745.93
  5. Step 5: Solve for x
    x = 203,745.93/666.15
  6. Step 6: Final answer
    x = 305.86

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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.