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Finding the Fourth Proportional to 426.56, 640.45 and 279.85

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Solution

The fourth proportional to 426.56, 640.45 and 279.85 is: 420.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.56 : 640.45 = 279.85 : x
  2. Step 2: Convert to fraction form
    426.56/640.45 = 279.85/x
  3. Step 3: Cross multiply
    426.56x = 640.45 × 279.85
  4. Step 4: Simplify right side
    426.56x = 179,229.93
  5. Step 5: Solve for x
    x = 179,229.93/426.56
  6. Step 6: Final answer
    x = 420.18

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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.