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Finding the Fourth Proportional to 425.25, 638.18 and 279

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Solution

The fourth proportional to 425.25, 638.18 and 279 is: 418.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.25 : 638.18 = 279 : x
  2. Step 2: Convert to fraction form
    425.25/638.18 = 279/x
  3. Step 3: Cross multiply
    425.25x = 638.18 × 279
  4. Step 4: Simplify right side
    425.25x = 178,050.83
  5. Step 5: Solve for x
    x = 178,050.83/425.25
  6. Step 6: Final answer
    x = 418.70

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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.