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Finding the Fourth Proportional to 80.19, 109.80 and 77.76

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Solution

The fourth proportional to 80.19, 109.80 and 77.76 is: 106.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.19 : 109.80 = 77.76 : x
  2. Step 2: Convert to fraction form
    80.19/109.80 = 77.76/x
  3. Step 3: Cross multiply
    80.19x = 109.80 × 77.76
  4. Step 4: Simplify right side
    80.19x = 8,538.05
  5. Step 5: Solve for x
    x = 8,538.05/80.19
  6. Step 6: Final answer
    x = 106.47

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.