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Finding the Fourth Proportional to 192.78, 289.09 and 77.28

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Solution

The fourth proportional to 192.78, 289.09 and 77.28 is: 115.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    192.78 : 289.09 = 77.28 : x
  2. Step 2: Convert to fraction form
    192.78/289.09 = 77.28/x
  3. Step 3: Cross multiply
    192.78x = 289.09 × 77.28
  4. Step 4: Simplify right side
    192.78x = 22,340.92
  5. Step 5: Solve for x
    x = 22,340.92/192.78
  6. Step 6: Final answer
    x = 115.89

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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.