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Finding the Fourth Proportional to 128.85, 193.36 and 51.80

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Solution

The fourth proportional to 128.85, 193.36 and 51.80 is: 77.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.85 : 193.36 = 51.80 : x
  2. Step 2: Convert to fraction form
    128.85/193.36 = 51.80/x
  3. Step 3: Cross multiply
    128.85x = 193.36 × 51.80
  4. Step 4: Simplify right side
    128.85x = 10,016.05
  5. Step 5: Solve for x
    x = 10,016.05/128.85
  6. Step 6: Final answer
    x = 77.73

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.