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Finding the Fourth Proportional to 778.17, 1,073.79 and 428.79

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Solution

The fourth proportional to 778.17, 1,073.79 and 428.79 is: 591.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.17 : 1,073.79 = 428.79 : x
  2. Step 2: Convert to fraction form
    778.17/1,073.79 = 428.79/x
  3. Step 3: Cross multiply
    778.17x = 1,073.79 × 428.79
  4. Step 4: Simplify right side
    778.17x = 460,430.41
  5. Step 5: Solve for x
    x = 460,430.41/778.17
  6. Step 6: Final answer
    x = 591.68

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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.