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Finding the Fourth Proportional to 659.69, 989.21 and 385.87

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Solution

The fourth proportional to 659.69, 989.21 and 385.87 is: 578.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.69 : 989.21 = 385.87 : x
  2. Step 2: Convert to fraction form
    659.69/989.21 = 385.87/x
  3. Step 3: Cross multiply
    659.69x = 989.21 × 385.87
  4. Step 4: Simplify right side
    659.69x = 381,706.46
  5. Step 5: Solve for x
    x = 381,706.46/659.69
  6. Step 6: Final answer
    x = 578.61

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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.