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Finding the Fourth Proportional to 660.08, 990.32 and 221.28

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Solution

The fourth proportional to 660.08, 990.32 and 221.28 is: 331.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.08 : 990.32 = 221.28 : x
  2. Step 2: Convert to fraction form
    660.08/990.32 = 221.28/x
  3. Step 3: Cross multiply
    660.08x = 990.32 × 221.28
  4. Step 4: Simplify right side
    660.08x = 219,138.01
  5. Step 5: Solve for x
    x = 219,138.01/660.08
  6. Step 6: Final answer
    x = 331.99

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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.