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Finding the Fourth Proportional to 660.96, 991.91 and 387.13

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Solution

The fourth proportional to 660.96, 991.91 and 387.13 is: 580.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.96 : 991.91 = 387.13 : x
  2. Step 2: Convert to fraction form
    660.96/991.91 = 387.13/x
  3. Step 3: Cross multiply
    660.96x = 991.91 × 387.13
  4. Step 4: Simplify right side
    660.96x = 383,998.12
  5. Step 5: Solve for x
    x = 383,998.12/660.96
  6. Step 6: Final answer
    x = 580.97

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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.