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Finding the Fourth Proportional to 80.85, 111.56 and 51.36

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Solution

The fourth proportional to 80.85, 111.56 and 51.36 is: 70.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.85 : 111.56 = 51.36 : x
  2. Step 2: Convert to fraction form
    80.85/111.56 = 51.36/x
  3. Step 3: Cross multiply
    80.85x = 111.56 × 51.36
  4. Step 4: Simplify right side
    80.85x = 5,729.96
  5. Step 5: Solve for x
    x = 5,729.96/80.85
  6. Step 6: Final answer
    x = 70.87

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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.