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Finding the Fourth Proportional to 79.82, 120.33 and 78.78

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Solution

The fourth proportional to 79.82, 120.33 and 78.78 is: 118.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.82 : 120.33 = 78.78 : x
  2. Step 2: Convert to fraction form
    79.82/120.33 = 78.78/x
  3. Step 3: Cross multiply
    79.82x = 120.33 × 78.78
  4. Step 4: Simplify right side
    79.82x = 9,479.60
  5. Step 5: Solve for x
    x = 9,479.60/79.82
  6. Step 6: Final answer
    x = 118.77

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.