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Finding the Fourth Proportional to 660.79, 991.18 and 198.55

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Solution

The fourth proportional to 660.79, 991.18 and 198.55 is: 297.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.79 : 991.18 = 198.55 : x
  2. Step 2: Convert to fraction form
    660.79/991.18 = 198.55/x
  3. Step 3: Cross multiply
    660.79x = 991.18 × 198.55
  4. Step 4: Simplify right side
    660.79x = 196,798.79
  5. Step 5: Solve for x
    x = 196,798.79/660.79
  6. Step 6: Final answer
    x = 297.82

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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.