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Finding the Fourth Proportional to 429.84, 643.14 and 321.30

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Solution

The fourth proportional to 429.84, 643.14 and 321.30 is: 480.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.84 : 643.14 = 321.30 : x
  2. Step 2: Convert to fraction form
    429.84/643.14 = 321.30/x
  3. Step 3: Cross multiply
    429.84x = 643.14 × 321.30
  4. Step 4: Simplify right side
    429.84x = 206,640.88
  5. Step 5: Solve for x
    x = 206,640.88/429.84
  6. Step 6: Final answer
    x = 480.74

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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.