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Finding the Fourth Proportional to 426.31, 639.61 and 253.12

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Solution

The fourth proportional to 426.31, 639.61 and 253.12 is: 379.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.31 : 639.61 = 253.12 : x
  2. Step 2: Convert to fraction form
    426.31/639.61 = 253.12/x
  3. Step 3: Cross multiply
    426.31x = 639.61 × 253.12
  4. Step 4: Simplify right side
    426.31x = 161,898.08
  5. Step 5: Solve for x
    x = 161,898.08/426.31
  6. Step 6: Final answer
    x = 379.77

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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.