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Finding the Fourth Proportional to 79.26, 108.72 and 78.54

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Solution

The fourth proportional to 79.26, 108.72 and 78.54 is: 107.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.26 : 108.72 = 78.54 : x
  2. Step 2: Convert to fraction form
    79.26/108.72 = 78.54/x
  3. Step 3: Cross multiply
    79.26x = 108.72 × 78.54
  4. Step 4: Simplify right side
    79.26x = 8,538.87
  5. Step 5: Solve for x
    x = 8,538.87/79.26
  6. Step 6: Final answer
    x = 107.73

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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.