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Finding the Fourth Proportional to 80.92, 111.45 and 72.13

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Solution

The fourth proportional to 80.92, 111.45 and 72.13 is: 99.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.92 : 111.45 = 72.13 : x
  2. Step 2: Convert to fraction form
    80.92/111.45 = 72.13/x
  3. Step 3: Cross multiply
    80.92x = 111.45 × 72.13
  4. Step 4: Simplify right side
    80.92x = 8,038.89
  5. Step 5: Solve for x
    x = 8,038.89/80.92
  6. Step 6: Final answer
    x = 99.34

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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.