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Finding the Fourth Proportional to 138.28, 190.78 and 79.27

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Solution

The fourth proportional to 138.28, 190.78 and 79.27 is: 109.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.28 : 190.78 = 79.27 : x
  2. Step 2: Convert to fraction form
    138.28/190.78 = 79.27/x
  3. Step 3: Cross multiply
    138.28x = 190.78 × 79.27
  4. Step 4: Simplify right side
    138.28x = 15,123.13
  5. Step 5: Solve for x
    x = 15,123.13/138.28
  6. Step 6: Final answer
    x = 109.37

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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.