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Finding the Fourth Proportional to 660.71, 991.20 and 198.45

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Solution

The fourth proportional to 660.71, 991.20 and 198.45 is: 297.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.71 : 991.20 = 198.45 : x
  2. Step 2: Convert to fraction form
    660.71/991.20 = 198.45/x
  3. Step 3: Cross multiply
    660.71x = 991.20 × 198.45
  4. Step 4: Simplify right side
    660.71x = 196,704.38
  5. Step 5: Solve for x
    x = 196,704.38/660.71
  6. Step 6: Final answer
    x = 297.72

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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.