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Finding the Fourth Proportional to 660.80, 990.90 and 198.42

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Solution

The fourth proportional to 660.80, 990.90 and 198.42 is: 297.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.80 : 990.90 = 198.42 : x
  2. Step 2: Convert to fraction form
    660.80/990.90 = 198.42/x
  3. Step 3: Cross multiply
    660.80x = 990.90 × 198.42
  4. Step 4: Simplify right side
    660.80x = 196,614.38
  5. Step 5: Solve for x
    x = 196,614.38/660.80
  6. Step 6: Final answer
    x = 297.54

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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.