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Finding the Fourth Proportional to 139.36, 192.36 and 86.91

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Solution

The fourth proportional to 139.36, 192.36 and 86.91 is: 119.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.36 : 192.36 = 86.91 : x
  2. Step 2: Convert to fraction form
    139.36/192.36 = 86.91/x
  3. Step 3: Cross multiply
    139.36x = 192.36 × 86.91
  4. Step 4: Simplify right side
    139.36x = 16,718.01
  5. Step 5: Solve for x
    x = 16,718.01/139.36
  6. Step 6: Final answer
    x = 119.96

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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.