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Finding the Fourth Proportional to 84.18, 115.29 and 81.48

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Solution

The fourth proportional to 84.18, 115.29 and 81.48 is: 111.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.18 : 115.29 = 81.48 : x
  2. Step 2: Convert to fraction form
    84.18/115.29 = 81.48/x
  3. Step 3: Cross multiply
    84.18x = 115.29 × 81.48
  4. Step 4: Simplify right side
    84.18x = 9,393.83
  5. Step 5: Solve for x
    x = 9,393.83/84.18
  6. Step 6: Final answer
    x = 111.59

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.