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Finding the Fourth Proportional to 81.88, 113.10 and 71.16

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Solution

The fourth proportional to 81.88, 113.10 and 71.16 is: 98.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.88 : 113.10 = 71.16 : x
  2. Step 2: Convert to fraction form
    81.88/113.10 = 71.16/x
  3. Step 3: Cross multiply
    81.88x = 113.10 × 71.16
  4. Step 4: Simplify right side
    81.88x = 8,048.20
  5. Step 5: Solve for x
    x = 8,048.20/81.88
  6. Step 6: Final answer
    x = 98.29

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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.