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Finding the Fourth Proportional to 3.86, 5.78 and 2.86

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Solution

The fourth proportional to 3.86, 5.78 and 2.86 is: 4.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.86 : 5.78 = 2.86 : x
  2. Step 2: Convert to fraction form
    3.86/5.78 = 2.86/x
  3. Step 3: Cross multiply
    3.86x = 5.78 × 2.86
  4. Step 4: Simplify right side
    3.86x = 16.53
  5. Step 5: Solve for x
    x = 16.53/3.86
  6. Step 6: Final answer
    x = 4.28

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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.