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Finding the Fourth Proportional to 778.09, 1,073.78 and 428.77

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Solution

The fourth proportional to 778.09, 1,073.78 and 428.77 is: 591.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.09 : 1,073.78 = 428.77 : x
  2. Step 2: Convert to fraction form
    778.09/1,073.78 = 428.77/x
  3. Step 3: Cross multiply
    778.09x = 1,073.78 × 428.77
  4. Step 4: Simplify right side
    778.09x = 460,404.65
  5. Step 5: Solve for x
    x = 460,404.65/778.09
  6. Step 6: Final answer
    x = 591.71

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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.