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Finding the Fourth Proportional to 198.38, 297.68 and 90.20

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Solution

The fourth proportional to 198.38, 297.68 and 90.20 is: 135.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.38 : 297.68 = 90.20 : x
  2. Step 2: Convert to fraction form
    198.38/297.68 = 90.20/x
  3. Step 3: Cross multiply
    198.38x = 297.68 × 90.20
  4. Step 4: Simplify right side
    198.38x = 26,848.80
  5. Step 5: Solve for x
    x = 26,848.80/198.38
  6. Step 6: Final answer
    x = 135.34

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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.