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Finding the Fourth Proportional to 660.43, 990.65 and 198.21

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Solution

The fourth proportional to 660.43, 990.65 and 198.21 is: 297.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.43 : 990.65 = 198.21 : x
  2. Step 2: Convert to fraction form
    660.43/990.65 = 198.21/x
  3. Step 3: Cross multiply
    660.43x = 990.65 × 198.21
  4. Step 4: Simplify right side
    660.43x = 196,359.83
  5. Step 5: Solve for x
    x = 196,359.83/660.43
  6. Step 6: Final answer
    x = 297.32

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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.