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Finding the Fourth Proportional to 2.11, 3.18 and 1.89

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Solution

The fourth proportional to 2.11, 3.18 and 1.89 is: 2.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.11 : 3.18 = 1.89 : x
  2. Step 2: Convert to fraction form
    2.11/3.18 = 1.89/x
  3. Step 3: Cross multiply
    2.11x = 3.18 × 1.89
  4. Step 4: Simplify right side
    2.11x = 6.01
  5. Step 5: Solve for x
    x = 6.01/2.11
  6. Step 6: Final answer
    x = 2.85

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.