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Finding the Fourth Proportional to 80.42, 109.52 and 78.92

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Solution

The fourth proportional to 80.42, 109.52 and 78.92 is: 107.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.42 : 109.52 = 78.92 : x
  2. Step 2: Convert to fraction form
    80.42/109.52 = 78.92/x
  3. Step 3: Cross multiply
    80.42x = 109.52 × 78.92
  4. Step 4: Simplify right side
    80.42x = 8,643.32
  5. Step 5: Solve for x
    x = 8,643.32/80.42
  6. Step 6: Final answer
    x = 107.48

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.