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Finding the Fourth Proportional to 139.49, 192.48 and 77.31

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Solution

The fourth proportional to 139.49, 192.48 and 77.31 is: 106.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.49 : 192.48 = 77.31 : x
  2. Step 2: Convert to fraction form
    139.49/192.48 = 77.31/x
  3. Step 3: Cross multiply
    139.49x = 192.48 × 77.31
  4. Step 4: Simplify right side
    139.49x = 14,880.63
  5. Step 5: Solve for x
    x = 14,880.63/139.49
  6. Step 6: Final answer
    x = 106.68

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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.