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Finding the Fourth Proportional to 429.80, 644.67 and 213.30

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Solution

The fourth proportional to 429.80, 644.67 and 213.30 is: 319.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.80 : 644.67 = 213.30 : x
  2. Step 2: Convert to fraction form
    429.80/644.67 = 213.30/x
  3. Step 3: Cross multiply
    429.80x = 644.67 × 213.30
  4. Step 4: Simplify right side
    429.80x = 137,508.11
  5. Step 5: Solve for x
    x = 137,508.11/429.80
  6. Step 6: Final answer
    x = 319.94

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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.