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Finding the Fourth Proportional to 660.57, 990.86 and 198.40

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Solution

The fourth proportional to 660.57, 990.86 and 198.40 is: 297.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.57 : 990.86 = 198.40 : x
  2. Step 2: Convert to fraction form
    660.57/990.86 = 198.40/x
  3. Step 3: Cross multiply
    660.57x = 990.86 × 198.40
  4. Step 4: Simplify right side
    660.57x = 196,588.36
  5. Step 5: Solve for x
    x = 196,588.36/660.57
  6. Step 6: Final answer
    x = 297.60

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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.