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Finding the Fourth Proportional to 81.58, 111.77 and 79.60

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Solution

The fourth proportional to 81.58, 111.77 and 79.60 is: 109.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.58 : 111.77 = 79.60 : x
  2. Step 2: Convert to fraction form
    81.58/111.77 = 79.60/x
  3. Step 3: Cross multiply
    81.58x = 111.77 × 79.60
  4. Step 4: Simplify right side
    81.58x = 8,896.89
  5. Step 5: Solve for x
    x = 8,896.89/81.58
  6. Step 6: Final answer
    x = 109.06

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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.