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Finding the Fourth Proportional to 659.97, 989.98 and 221.25

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Solution

The fourth proportional to 659.97, 989.98 and 221.25 is: 331.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.97 : 989.98 = 221.25 : x
  2. Step 2: Convert to fraction form
    659.97/989.98 = 221.25/x
  3. Step 3: Cross multiply
    659.97x = 989.98 × 221.25
  4. Step 4: Simplify right side
    659.97x = 219,033.08
  5. Step 5: Solve for x
    x = 219,033.08/659.97
  6. Step 6: Final answer
    x = 331.88

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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.