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Finding the Fourth Proportional to 659.39, 987.67 and 427.60

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Solution

The fourth proportional to 659.39, 987.67 and 427.60 is: 640.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.39 : 987.67 = 427.60 : x
  2. Step 2: Convert to fraction form
    659.39/987.67 = 427.60/x
  3. Step 3: Cross multiply
    659.39x = 987.67 × 427.60
  4. Step 4: Simplify right side
    659.39x = 422,331.04
  5. Step 5: Solve for x
    x = 422,331.04/659.39
  6. Step 6: Final answer
    x = 640.49

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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.