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Finding the Fourth Proportional to 660.75, 991.21 and 198.56

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Solution

The fourth proportional to 660.75, 991.21 and 198.56 is: 297.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.75 : 991.21 = 198.56 : x
  2. Step 2: Convert to fraction form
    660.75/991.21 = 198.56/x
  3. Step 3: Cross multiply
    660.75x = 991.21 × 198.56
  4. Step 4: Simplify right side
    660.75x = 196,814.66
  5. Step 5: Solve for x
    x = 196,814.66/660.75
  6. Step 6: Final answer
    x = 297.87

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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.