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Finding the Fourth Proportional to 80.77, 111.20 and 71.86

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Solution

The fourth proportional to 80.77, 111.20 and 71.86 is: 98.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.77 : 111.20 = 71.86 : x
  2. Step 2: Convert to fraction form
    80.77/111.20 = 71.86/x
  3. Step 3: Cross multiply
    80.77x = 111.20 × 71.86
  4. Step 4: Simplify right side
    80.77x = 7,990.83
  5. Step 5: Solve for x
    x = 7,990.83/80.77
  6. Step 6: Final answer
    x = 98.93

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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.