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Finding the Fourth Proportional to 2.78, 3.81 and 2.57

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Solution

The fourth proportional to 2.78, 3.81 and 2.57 is: 3.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.78 : 3.81 = 2.57 : x
  2. Step 2: Convert to fraction form
    2.78/3.81 = 2.57/x
  3. Step 3: Cross multiply
    2.78x = 3.81 × 2.57
  4. Step 4: Simplify right side
    2.78x = 9.77
  5. Step 5: Solve for x
    x = 9.77/2.78
  6. Step 6: Final answer
    x = 3.52

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.