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Finding the Fourth Proportional to 427.05, 640.17 and 289.80

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Solution

The fourth proportional to 427.05, 640.17 and 289.80 is: 434.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.05 : 640.17 = 289.80 : x
  2. Step 2: Convert to fraction form
    427.05/640.17 = 289.80/x
  3. Step 3: Cross multiply
    427.05x = 640.17 × 289.80
  4. Step 4: Simplify right side
    427.05x = 185,521.27
  5. Step 5: Solve for x
    x = 185,521.27/427.05
  6. Step 6: Final answer
    x = 434.43

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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.