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Finding the Fourth Proportional to 659.75, 987.87 and 427.97

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Solution

The fourth proportional to 659.75, 987.87 and 427.97 is: 640.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.75 : 987.87 = 427.97 : x
  2. Step 2: Convert to fraction form
    659.75/987.87 = 427.97/x
  3. Step 3: Cross multiply
    659.75x = 987.87 × 427.97
  4. Step 4: Simplify right side
    659.75x = 422,778.72
  5. Step 5: Solve for x
    x = 422,778.72/659.75
  6. Step 6: Final answer
    x = 640.82

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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.