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Finding the Fourth Proportional to 28.78, 39.81 and 25.71

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Solution

The fourth proportional to 28.78, 39.81 and 25.71 is: 35.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.78 : 39.81 = 25.71 : x
  2. Step 2: Convert to fraction form
    28.78/39.81 = 25.71/x
  3. Step 3: Cross multiply
    28.78x = 39.81 × 25.71
  4. Step 4: Simplify right side
    28.78x = 1,023.19
  5. Step 5: Solve for x
    x = 1,023.19/28.78
  6. Step 6: Final answer
    x = 35.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.