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Finding the Fourth Proportional to 789.18, 1,089 and 439.86

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Solution

The fourth proportional to 789.18, 1,089 and 439.86 is: 606.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.18 : 1,089 = 439.86 : x
  2. Step 2: Convert to fraction form
    789.18/1,089 = 439.86/x
  3. Step 3: Cross multiply
    789.18x = 1,089 × 439.86
  4. Step 4: Simplify right side
    789.18x = 479,007.54
  5. Step 5: Solve for x
    x = 479,007.54/789.18
  6. Step 6: Final answer
    x = 606.97

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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.