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Finding the Fourth Proportional to 5.11, 7.05 and 3.90

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Solution

The fourth proportional to 5.11, 7.05 and 3.90 is: 5.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.11 : 7.05 = 3.90 : x
  2. Step 2: Convert to fraction form
    5.11/7.05 = 3.90/x
  3. Step 3: Cross multiply
    5.11x = 7.05 × 3.90
  4. Step 4: Simplify right side
    5.11x = 27.50
  5. Step 5: Solve for x
    x = 27.50/5.11
  6. Step 6: Final answer
    x = 5.38

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.