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Finding the Fourth Proportional to 80.62, 110.92 and 78.80

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Solution

The fourth proportional to 80.62, 110.92 and 78.80 is: 108.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.62 : 110.92 = 78.80 : x
  2. Step 2: Convert to fraction form
    80.62/110.92 = 78.80/x
  3. Step 3: Cross multiply
    80.62x = 110.92 × 78.80
  4. Step 4: Simplify right side
    80.62x = 8,740.50
  5. Step 5: Solve for x
    x = 8,740.50/80.62
  6. Step 6: Final answer
    x = 108.42

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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.