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Finding the Fourth Proportional to 3.87, 5.81 and 1.87

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Solution

The fourth proportional to 3.87, 5.81 and 1.87 is: 2.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.87 : 5.81 = 1.87 : x
  2. Step 2: Convert to fraction form
    3.87/5.81 = 1.87/x
  3. Step 3: Cross multiply
    3.87x = 5.81 × 1.87
  4. Step 4: Simplify right side
    3.87x = 10.86
  5. Step 5: Solve for x
    x = 10.86/3.87
  6. Step 6: Final answer
    x = 2.80

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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.