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Finding the Fourth Proportional to 139.04, 191.88 and 83.80

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Solution

The fourth proportional to 139.04, 191.88 and 83.80 is: 115.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.04 : 191.88 = 83.80 : x
  2. Step 2: Convert to fraction form
    139.04/191.88 = 83.80/x
  3. Step 3: Cross multiply
    139.04x = 191.88 × 83.80
  4. Step 4: Simplify right side
    139.04x = 16,079.54
  5. Step 5: Solve for x
    x = 16,079.54/139.04
  6. Step 6: Final answer
    x = 115.65

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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.