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Finding the Fourth Proportional to 660.87, 991.30 and 198.64

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Solution

The fourth proportional to 660.87, 991.30 and 198.64 is: 297.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.87 : 991.30 = 198.64 : x
  2. Step 2: Convert to fraction form
    660.87/991.30 = 198.64/x
  3. Step 3: Cross multiply
    660.87x = 991.30 × 198.64
  4. Step 4: Simplify right side
    660.87x = 196,913.81
  5. Step 5: Solve for x
    x = 196,913.81/660.87
  6. Step 6: Final answer
    x = 297.96

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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.