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Finding the Fourth Proportional to 3.98, 5.98 and 3.90

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Solution

The fourth proportional to 3.98, 5.98 and 3.90 is: 5.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.98 : 5.98 = 3.90 : x
  2. Step 2: Convert to fraction form
    3.98/5.98 = 3.90/x
  3. Step 3: Cross multiply
    3.98x = 5.98 × 3.90
  4. Step 4: Simplify right side
    3.98x = 23.32
  5. Step 5: Solve for x
    x = 23.32/3.98
  6. Step 6: Final answer
    x = 5.86

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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.