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Finding the Fourth Proportional to 660.72, 911.92 and 395.18

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Solution

The fourth proportional to 660.72, 911.92 and 395.18 is: 545.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.72 : 911.92 = 395.18 : x
  2. Step 2: Convert to fraction form
    660.72/911.92 = 395.18/x
  3. Step 3: Cross multiply
    660.72x = 911.92 × 395.18
  4. Step 4: Simplify right side
    660.72x = 360,372.55
  5. Step 5: Solve for x
    x = 360,372.55/660.72
  6. Step 6: Final answer
    x = 545.42

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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.