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Finding the Fourth Proportional to 80.45, 110.89 and 78.76

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Solution

The fourth proportional to 80.45, 110.89 and 78.76 is: 108.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.45 : 110.89 = 78.76 : x
  2. Step 2: Convert to fraction form
    80.45/110.89 = 78.76/x
  3. Step 3: Cross multiply
    80.45x = 110.89 × 78.76
  4. Step 4: Simplify right side
    80.45x = 8,733.70
  5. Step 5: Solve for x
    x = 8,733.70/80.45
  6. Step 6: Final answer
    x = 108.56

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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.