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Finding the Fourth Proportional to 198.70, 298.05 and 90.49

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Solution

The fourth proportional to 198.70, 298.05 and 90.49 is: 135.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.70 : 298.05 = 90.49 : x
  2. Step 2: Convert to fraction form
    198.70/298.05 = 90.49/x
  3. Step 3: Cross multiply
    198.70x = 298.05 × 90.49
  4. Step 4: Simplify right side
    198.70x = 26,970.54
  5. Step 5: Solve for x
    x = 26,970.54/198.70
  6. Step 6: Final answer
    x = 135.74

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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.