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Finding the Fourth Proportional to 2.20, 3.31 and 1.87

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Solution

The fourth proportional to 2.20, 3.31 and 1.87 is: 2.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.20 : 3.31 = 1.87 : x
  2. Step 2: Convert to fraction form
    2.20/3.31 = 1.87/x
  3. Step 3: Cross multiply
    2.20x = 3.31 × 1.87
  4. Step 4: Simplify right side
    2.20x = 6.18
  5. Step 5: Solve for x
    x = 6.18/2.20
  6. Step 6: Final answer
    x = 2.81

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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.