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Finding the Fourth Proportional to 660.97, 991.09 and 387.15

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Solution

The fourth proportional to 660.97, 991.09 and 387.15 is: 580.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.97 : 991.09 = 387.15 : x
  2. Step 2: Convert to fraction form
    660.97/991.09 = 387.15/x
  3. Step 3: Cross multiply
    660.97x = 991.09 × 387.15
  4. Step 4: Simplify right side
    660.97x = 383,700.49
  5. Step 5: Solve for x
    x = 383,700.49/660.97
  6. Step 6: Final answer
    x = 580.51

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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.