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Finding the Fourth Proportional to 429.71, 644.34 and 198.40

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Solution

The fourth proportional to 429.71, 644.34 and 198.40 is: 297.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.71 : 644.34 = 198.40 : x
  2. Step 2: Convert to fraction form
    429.71/644.34 = 198.40/x
  3. Step 3: Cross multiply
    429.71x = 644.34 × 198.40
  4. Step 4: Simplify right side
    429.71x = 127,835.45
  5. Step 5: Solve for x
    x = 127,835.45/429.71
  6. Step 6: Final answer
    x = 297.49

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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.