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Finding the Fourth Proportional to 659.91, 989.88 and 221.16

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Solution

The fourth proportional to 659.91, 989.88 and 221.16 is: 331.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.91 : 989.88 = 221.16 : x
  2. Step 2: Convert to fraction form
    659.91/989.88 = 221.16/x
  3. Step 3: Cross multiply
    659.91x = 989.88 × 221.16
  4. Step 4: Simplify right side
    659.91x = 218,921.86
  5. Step 5: Solve for x
    x = 218,921.86/659.91
  6. Step 6: Final answer
    x = 331.75

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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.