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Finding the Fourth Proportional to 666.17, 998.57 and 391.43

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Solution

The fourth proportional to 666.17, 998.57 and 391.43 is: 586.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.17 : 998.57 = 391.43 : x
  2. Step 2: Convert to fraction form
    666.17/998.57 = 391.43/x
  3. Step 3: Cross multiply
    666.17x = 998.57 × 391.43
  4. Step 4: Simplify right side
    666.17x = 390,865.26
  5. Step 5: Solve for x
    x = 390,865.26/666.17
  6. Step 6: Final answer
    x = 586.74

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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.