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Finding the Fourth Proportional to 561.72, 840.87 and 489.72

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Solution

The fourth proportional to 561.72, 840.87 and 489.72 is: 733.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.72 : 840.87 = 489.72 : x
  2. Step 2: Convert to fraction form
    561.72/840.87 = 489.72/x
  3. Step 3: Cross multiply
    561.72x = 840.87 × 489.72
  4. Step 4: Simplify right side
    561.72x = 411,790.86
  5. Step 5: Solve for x
    x = 411,790.86/561.72
  6. Step 6: Final answer
    x = 733.09

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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.