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Finding the Fourth Proportional to 660.56, 990.50 and 221.66

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Solution

The fourth proportional to 660.56, 990.50 and 221.66 is: 332.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.56 : 990.50 = 221.66 : x
  2. Step 2: Convert to fraction form
    660.56/990.50 = 221.66/x
  3. Step 3: Cross multiply
    660.56x = 990.50 × 221.66
  4. Step 4: Simplify right side
    660.56x = 219,554.23
  5. Step 5: Solve for x
    x = 219,554.23/660.56
  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.