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Finding the Fourth Proportional to 660.92, 911.86 and 638.20

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Solution

The fourth proportional to 660.92, 911.86 and 638.20 is: 880.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.92 : 911.86 = 638.20 : x
  2. Step 2: Convert to fraction form
    660.92/911.86 = 638.20/x
  3. Step 3: Cross multiply
    660.92x = 911.86 × 638.20
  4. Step 4: Simplify right side
    660.92x = 581,949.05
  5. Step 5: Solve for x
    x = 581,949.05/660.92
  6. Step 6: Final answer
    x = 880.51

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.