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Finding the Fourth Proportional to 429.78, 643.17 and 265.17

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Solution

The fourth proportional to 429.78, 643.17 and 265.17 is: 396.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.78 : 643.17 = 265.17 : x
  2. Step 2: Convert to fraction form
    429.78/643.17 = 265.17/x
  3. Step 3: Cross multiply
    429.78x = 643.17 × 265.17
  4. Step 4: Simplify right side
    429.78x = 170,549.39
  5. Step 5: Solve for x
    x = 170,549.39/429.78
  6. Step 6: Final answer
    x = 396.83

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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.