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Finding the Fourth Proportional to 426.79, 640.19 and 289.97

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Solution

The fourth proportional to 426.79, 640.19 and 289.97 is: 434.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.79 : 640.19 = 289.97 : x
  2. Step 2: Convert to fraction form
    426.79/640.19 = 289.97/x
  3. Step 3: Cross multiply
    426.79x = 640.19 × 289.97
  4. Step 4: Simplify right side
    426.79x = 185,635.89
  5. Step 5: Solve for x
    x = 185,635.89/426.79
  6. Step 6: Final answer
    x = 434.96

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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.