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Finding the Fourth Proportional to 659.65, 989.37 and 220.90

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Solution

The fourth proportional to 659.65, 989.37 and 220.90 is: 331.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.65 : 989.37 = 220.90 : x
  2. Step 2: Convert to fraction form
    659.65/989.37 = 220.90/x
  3. Step 3: Cross multiply
    659.65x = 989.37 × 220.90
  4. Step 4: Simplify right side
    659.65x = 218,545.78
  5. Step 5: Solve for x
    x = 218,545.78/659.65
  6. Step 6: Final answer
    x = 331.31

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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.