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Finding the Fourth Proportional to 137.28, 205.92 and 51.78

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Solution

The fourth proportional to 137.28, 205.92 and 51.78 is: 77.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.28 : 205.92 = 51.78 : x
  2. Step 2: Convert to fraction form
    137.28/205.92 = 51.78/x
  3. Step 3: Cross multiply
    137.28x = 205.92 × 51.78
  4. Step 4: Simplify right side
    137.28x = 10,662.54
  5. Step 5: Solve for x
    x = 10,662.54/137.28
  6. Step 6: Final answer
    x = 77.67

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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.