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Finding the Fourth Proportional to 81.88, 113.03 and 57.31

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Solution

The fourth proportional to 81.88, 113.03 and 57.31 is: 79.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.88 : 113.03 = 57.31 : x
  2. Step 2: Convert to fraction form
    81.88/113.03 = 57.31/x
  3. Step 3: Cross multiply
    81.88x = 113.03 × 57.31
  4. Step 4: Simplify right side
    81.88x = 6,477.75
  5. Step 5: Solve for x
    x = 6,477.75/81.88
  6. Step 6: Final answer
    x = 79.11

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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.