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Finding the Fourth Proportional to 425.00, 636.80 and 408.78

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Solution

The fourth proportional to 425.00, 636.80 and 408.78 is: 612.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.00 : 636.80 = 408.78 : x
  2. Step 2: Convert to fraction form
    425.00/636.80 = 408.78/x
  3. Step 3: Cross multiply
    425.00x = 636.80 × 408.78
  4. Step 4: Simplify right side
    425.00x = 260,309.06
  5. Step 5: Solve for x
    x = 260,309.06/425.00
  6. Step 6: Final answer
    x = 612.50

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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.