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Finding the Fourth Proportional to 102.78, 141.83 and 77.84

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Solution

The fourth proportional to 102.78, 141.83 and 77.84 is: 107.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.78 : 141.83 = 77.84 : x
  2. Step 2: Convert to fraction form
    102.78/141.83 = 77.84/x
  3. Step 3: Cross multiply
    102.78x = 141.83 × 77.84
  4. Step 4: Simplify right side
    102.78x = 11,040.60
  5. Step 5: Solve for x
    x = 11,040.60/102.78
  6. Step 6: Final answer
    x = 107.42

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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.