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Finding the Fourth Proportional to 660.92, 991.42 and 386.80

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Solution

The fourth proportional to 660.92, 991.42 and 386.80 is: 580.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.92 : 991.42 = 386.80 : x
  2. Step 2: Convert to fraction form
    660.92/991.42 = 386.80/x
  3. Step 3: Cross multiply
    660.92x = 991.42 × 386.80
  4. Step 4: Simplify right side
    660.92x = 383,481.26
  5. Step 5: Solve for x
    x = 383,481.26/660.92
  6. Step 6: Final answer
    x = 580.22

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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.