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Finding the Fourth Proportional to 100.82, 138.83 and 84.42

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Solution

The fourth proportional to 100.82, 138.83 and 84.42 is: 116.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.82 : 138.83 = 84.42 : x
  2. Step 2: Convert to fraction form
    100.82/138.83 = 84.42/x
  3. Step 3: Cross multiply
    100.82x = 138.83 × 84.42
  4. Step 4: Simplify right side
    100.82x = 11,718.91
  5. Step 5: Solve for x
    x = 11,718.91/100.82
  6. Step 6: Final answer
    x = 116.24

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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.