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Finding the Fourth Proportional to 72.75, 100.85 and 68.09

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Solution

The fourth proportional to 72.75, 100.85 and 68.09 is: 94.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.75 : 100.85 = 68.09 : x
  2. Step 2: Convert to fraction form
    72.75/100.85 = 68.09/x
  3. Step 3: Cross multiply
    72.75x = 100.85 × 68.09
  4. Step 4: Simplify right side
    72.75x = 6,866.60
  5. Step 5: Solve for x
    x = 6,866.60/72.75
  6. Step 6: Final answer
    x = 94.39

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.