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Finding the Fourth Proportional to 429.35, 643.61 and 198.39

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Solution

The fourth proportional to 429.35, 643.61 and 198.39 is: 297.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.35 : 643.61 = 198.39 : x
  2. Step 2: Convert to fraction form
    429.35/643.61 = 198.39/x
  3. Step 3: Cross multiply
    429.35x = 643.61 × 198.39
  4. Step 4: Simplify right side
    429.35x = 127,685.79
  5. Step 5: Solve for x
    x = 127,685.79/429.35
  6. Step 6: Final answer
    x = 297.39

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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.