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Finding the Fourth Proportional to 426.60, 640.50 and 280.38

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Solution

The fourth proportional to 426.60, 640.50 and 280.38 is: 420.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.60 : 640.50 = 280.38 : x
  2. Step 2: Convert to fraction form
    426.60/640.50 = 280.38/x
  3. Step 3: Cross multiply
    426.60x = 640.50 × 280.38
  4. Step 4: Simplify right side
    426.60x = 179,583.39
  5. Step 5: Solve for x
    x = 179,583.39/426.60
  6. Step 6: Final answer
    x = 420.96

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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.