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Finding the Fourth Proportional to 659.38, 987.68 and 427.59

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Solution

The fourth proportional to 659.38, 987.68 and 427.59 is: 640.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.38 : 987.68 = 427.59 : x
  2. Step 2: Convert to fraction form
    659.38/987.68 = 427.59/x
  3. Step 3: Cross multiply
    659.38x = 987.68 × 427.59
  4. Step 4: Simplify right side
    659.38x = 422,317.70
  5. Step 5: Solve for x
    x = 422,317.70/659.38
  6. Step 6: Final answer
    x = 640.47

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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.