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Finding the Fourth Proportional to 72.05, 107.31 and 69.92

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Solution

The fourth proportional to 72.05, 107.31 and 69.92 is: 104.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.05 : 107.31 = 69.92 : x
  2. Step 2: Convert to fraction form
    72.05/107.31 = 69.92/x
  3. Step 3: Cross multiply
    72.05x = 107.31 × 69.92
  4. Step 4: Simplify right side
    72.05x = 7,502.58
  5. Step 5: Solve for x
    x = 7,502.58/72.05
  6. Step 6: Final answer
    x = 104.14

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.