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Finding the Fourth Proportional to 79.85, 110.05 and 61.39

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Solution

The fourth proportional to 79.85, 110.05 and 61.39 is: 84.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.85 : 110.05 = 61.39 : x
  2. Step 2: Convert to fraction form
    79.85/110.05 = 61.39/x
  3. Step 3: Cross multiply
    79.85x = 110.05 × 61.39
  4. Step 4: Simplify right side
    79.85x = 6,755.97
  5. Step 5: Solve for x
    x = 6,755.97/79.85
  6. Step 6: Final answer
    x = 84.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.