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Finding the Fourth Proportional to 426.20, 639.40 and 233.78

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Solution

The fourth proportional to 426.20, 639.40 and 233.78 is: 350.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.20 : 639.40 = 233.78 : x
  2. Step 2: Convert to fraction form
    426.20/639.40 = 233.78/x
  3. Step 3: Cross multiply
    426.20x = 639.40 × 233.78
  4. Step 4: Simplify right side
    426.20x = 149,478.93
  5. Step 5: Solve for x
    x = 149,478.93/426.20
  6. Step 6: Final answer
    x = 350.72

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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.