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Finding the Fourth Proportional to 660.33, 990.39 and 221.61

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Solution

The fourth proportional to 660.33, 990.39 and 221.61 is: 332.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.33 : 990.39 = 221.61 : x
  2. Step 2: Convert to fraction form
    660.33/990.39 = 221.61/x
  3. Step 3: Cross multiply
    660.33x = 990.39 × 221.61
  4. Step 4: Simplify right side
    660.33x = 219,480.33
  5. Step 5: Solve for x
    x = 219,480.33/660.33
  6. Step 6: Final answer
    x = 332.38

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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.