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Finding the Fourth Proportional to 665.87, 997.43 and 391.13

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Solution

The fourth proportional to 665.87, 997.43 and 391.13 is: 585.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.87 : 997.43 = 391.13 : x
  2. Step 2: Convert to fraction form
    665.87/997.43 = 391.13/x
  3. Step 3: Cross multiply
    665.87x = 997.43 × 391.13
  4. Step 4: Simplify right side
    665.87x = 390,117.85
  5. Step 5: Solve for x
    x = 390,117.85/665.87
  6. Step 6: Final answer
    x = 585.88

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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.