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Finding the Fourth Proportional to 84.36, 125.91 and 72.74

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Solution

The fourth proportional to 84.36, 125.91 and 72.74 is: 108.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.36 : 125.91 = 72.74 : x
  2. Step 2: Convert to fraction form
    84.36/125.91 = 72.74/x
  3. Step 3: Cross multiply
    84.36x = 125.91 × 72.74
  4. Step 4: Simplify right side
    84.36x = 9,158.54
  5. Step 5: Solve for x
    x = 9,158.54/84.36
  6. Step 6: Final answer
    x = 108.56

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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.