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Finding the Fourth Proportional to 426.64, 639.82 and 289.76

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Solution

The fourth proportional to 426.64, 639.82 and 289.76 is: 434.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.64 : 639.82 = 289.76 : x
  2. Step 2: Convert to fraction form
    426.64/639.82 = 289.76/x
  3. Step 3: Cross multiply
    426.64x = 639.82 × 289.76
  4. Step 4: Simplify right side
    426.64x = 185,394.24
  5. Step 5: Solve for x
    x = 185,394.24/426.64
  6. Step 6: Final answer
    x = 434.54

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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.