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Finding the Fourth Proportional to 666.29, 998.39 and 319.61

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Solution

The fourth proportional to 666.29, 998.39 and 319.61 is: 478.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.29 : 998.39 = 319.61 : x
  2. Step 2: Convert to fraction form
    666.29/998.39 = 319.61/x
  3. Step 3: Cross multiply
    666.29x = 998.39 × 319.61
  4. Step 4: Simplify right side
    666.29x = 319,098.72
  5. Step 5: Solve for x
    x = 319,098.72/666.29
  6. Step 6: Final answer
    x = 478.92

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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.