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Finding the Fourth Proportional to 814.34, 1,221.15 and 429.86

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Solution

The fourth proportional to 814.34, 1,221.15 and 429.86 is: 644.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.34 : 1,221.15 = 429.86 : x
  2. Step 2: Convert to fraction form
    814.34/1,221.15 = 429.86/x
  3. Step 3: Cross multiply
    814.34x = 1,221.15 × 429.86
  4. Step 4: Simplify right side
    814.34x = 524,923.54
  5. Step 5: Solve for x
    x = 524,923.54/814.34
  6. Step 6: Final answer
    x = 644.60

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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.