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Finding the Fourth Proportional to 426.71, 640.20 and 221.43

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Solution

The fourth proportional to 426.71, 640.20 and 221.43 is: 332.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.71 : 640.20 = 221.43 : x
  2. Step 2: Convert to fraction form
    426.71/640.20 = 221.43/x
  3. Step 3: Cross multiply
    426.71x = 640.20 × 221.43
  4. Step 4: Simplify right side
    426.71x = 141,759.49
  5. Step 5: Solve for x
    x = 141,759.49/426.71
  6. Step 6: Final answer
    x = 332.22

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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.