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Finding the Fourth Proportional to 429.29, 643.59 and 220.71

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Solution

The fourth proportional to 429.29, 643.59 and 220.71 is: 330.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.29 : 643.59 = 220.71 : x
  2. Step 2: Convert to fraction form
    429.29/643.59 = 220.71/x
  3. Step 3: Cross multiply
    429.29x = 643.59 × 220.71
  4. Step 4: Simplify right side
    429.29x = 142,046.75
  5. Step 5: Solve for x
    x = 142,046.75/429.29
  6. Step 6: Final answer
    x = 330.89

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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.