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Finding the Fourth Proportional to 139.80, 194.21 and 135.72

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Solution

The fourth proportional to 139.80, 194.21 and 135.72 is: 188.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.80 : 194.21 = 135.72 : x
  2. Step 2: Convert to fraction form
    139.80/194.21 = 135.72/x
  3. Step 3: Cross multiply
    139.80x = 194.21 × 135.72
  4. Step 4: Simplify right side
    139.80x = 26,358.18
  5. Step 5: Solve for x
    x = 26,358.18/139.80
  6. Step 6: Final answer
    x = 188.54

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.