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Finding the Fourth Proportional to 660.79, 990.97 and 221.95

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Solution

The fourth proportional to 660.79, 990.97 and 221.95 is: 332.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.79 : 990.97 = 221.95 : x
  2. Step 2: Convert to fraction form
    660.79/990.97 = 221.95/x
  3. Step 3: Cross multiply
    660.79x = 990.97 × 221.95
  4. Step 4: Simplify right side
    660.79x = 219,945.79
  5. Step 5: Solve for x
    x = 219,945.79/660.79
  6. Step 6: Final answer
    x = 332.85

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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.