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Finding the Fourth Proportional to 429.77, 643.40 and 388.73

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Solution

The fourth proportional to 429.77, 643.40 and 388.73 is: 581.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.77 : 643.40 = 388.73 : x
  2. Step 2: Convert to fraction form
    429.77/643.40 = 388.73/x
  3. Step 3: Cross multiply
    429.77x = 643.40 × 388.73
  4. Step 4: Simplify right side
    429.77x = 250,107.91
  5. Step 5: Solve for x
    x = 250,107.91/429.77
  6. Step 6: Final answer
    x = 581.96

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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.