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Finding the Fourth Proportional to 660.30, 989.75 and 221.43

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Solution

The fourth proportional to 660.30, 989.75 and 221.43 is: 331.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.30 : 989.75 = 221.43 : x
  2. Step 2: Convert to fraction form
    660.30/989.75 = 221.43/x
  3. Step 3: Cross multiply
    660.30x = 989.75 × 221.43
  4. Step 4: Simplify right side
    660.30x = 219,160.34
  5. Step 5: Solve for x
    x = 219,160.34/660.30
  6. Step 6: Final answer
    x = 331.91

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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.