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Finding the Fourth Proportional to 91.23, 125.94 and 78.92

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Solution

The fourth proportional to 91.23, 125.94 and 78.92 is: 108.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.23 : 125.94 = 78.92 : x
  2. Step 2: Convert to fraction form
    91.23/125.94 = 78.92/x
  3. Step 3: Cross multiply
    91.23x = 125.94 × 78.92
  4. Step 4: Simplify right side
    91.23x = 9,939.32
  5. Step 5: Solve for x
    x = 9,939.32/91.23
  6. Step 6: Final answer
    x = 108.95

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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.