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Finding the Fourth Proportional to 80.99, 111.74 and 72.69

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Solution

The fourth proportional to 80.99, 111.74 and 72.69 is: 100.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.99 : 111.74 = 72.69 : x
  2. Step 2: Convert to fraction form
    80.99/111.74 = 72.69/x
  3. Step 3: Cross multiply
    80.99x = 111.74 × 72.69
  4. Step 4: Simplify right side
    80.99x = 8,122.38
  5. Step 5: Solve for x
    x = 8,122.38/80.99
  6. Step 6: Final answer
    x = 100.29

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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.