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Finding the Fourth Proportional to 426.20, 638.39 and 288.64

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Solution

The fourth proportional to 426.20, 638.39 and 288.64 is: 432.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.20 : 638.39 = 288.64 : x
  2. Step 2: Convert to fraction form
    426.20/638.39 = 288.64/x
  3. Step 3: Cross multiply
    426.20x = 638.39 × 288.64
  4. Step 4: Simplify right side
    426.20x = 184,264.02
  5. Step 5: Solve for x
    x = 184,264.02/426.20
  6. Step 6: Final answer
    x = 432.34

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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.