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Finding the Fourth Proportional to 79.46, 108.68 and 78.20

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Solution

The fourth proportional to 79.46, 108.68 and 78.20 is: 106.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.46 : 108.68 = 78.20 : x
  2. Step 2: Convert to fraction form
    79.46/108.68 = 78.20/x
  3. Step 3: Cross multiply
    79.46x = 108.68 × 78.20
  4. Step 4: Simplify right side
    79.46x = 8,498.78
  5. Step 5: Solve for x
    x = 8,498.78/79.46
  6. Step 6: Final answer
    x = 106.96

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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.