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Finding the Fourth Proportional to 661.17, 991.76 and 198.95

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Solution

The fourth proportional to 661.17, 991.76 and 198.95 is: 298.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.17 : 991.76 = 198.95 : x
  2. Step 2: Convert to fraction form
    661.17/991.76 = 198.95/x
  3. Step 3: Cross multiply
    661.17x = 991.76 × 198.95
  4. Step 4: Simplify right side
    661.17x = 197,304.70
  5. Step 5: Solve for x
    x = 197,304.70/661.17
  6. Step 6: Final answer
    x = 298.42

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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.