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Finding the Fourth Proportional to 139.72, 192.81 and 77.55

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Solution

The fourth proportional to 139.72, 192.81 and 77.55 is: 107.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.72 : 192.81 = 77.55 : x
  2. Step 2: Convert to fraction form
    139.72/192.81 = 77.55/x
  3. Step 3: Cross multiply
    139.72x = 192.81 × 77.55
  4. Step 4: Simplify right side
    139.72x = 14,953.34
  5. Step 5: Solve for x
    x = 14,953.34/139.72
  6. Step 6: Final answer
    x = 107.03

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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.