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Finding the Fourth Proportional to 427.05, 639.83 and 289.61

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Solution

The fourth proportional to 427.05, 639.83 and 289.61 is: 433.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.05 : 639.83 = 289.61 : x
  2. Step 2: Convert to fraction form
    427.05/639.83 = 289.61/x
  3. Step 3: Cross multiply
    427.05x = 639.83 × 289.61
  4. Step 4: Simplify right side
    427.05x = 185,296.52
  5. Step 5: Solve for x
    x = 185,296.52/427.05
  6. Step 6: Final answer
    x = 433.90

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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.