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Finding the Fourth Proportional to 81.24, 111.94 and 71.96

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Solution

The fourth proportional to 81.24, 111.94 and 71.96 is: 99.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.24 : 111.94 = 71.96 : x
  2. Step 2: Convert to fraction form
    81.24/111.94 = 71.96/x
  3. Step 3: Cross multiply
    81.24x = 111.94 × 71.96
  4. Step 4: Simplify right side
    81.24x = 8,055.20
  5. Step 5: Solve for x
    x = 8,055.20/81.24
  6. Step 6: Final answer
    x = 99.15

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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.