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Finding the Fourth Proportional to 666.05, 997.71 and 391.31

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Solution

The fourth proportional to 666.05, 997.71 and 391.31 is: 586.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.05 : 997.71 = 391.31 : x
  2. Step 2: Convert to fraction form
    666.05/997.71 = 391.31/x
  3. Step 3: Cross multiply
    666.05x = 997.71 × 391.31
  4. Step 4: Simplify right side
    666.05x = 390,413.90
  5. Step 5: Solve for x
    x = 390,413.90/666.05
  6. Step 6: Final answer
    x = 586.16

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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.