Finding the Fourth Proportional to 91.83, 137.76 and 77.25

Step by Step Solution

1. Step 1: Write the proportion equation
   91.83 : 137.76 = 77.25 : x
2. Step 2: Convert to fraction form
   91.83/137.76 = 77.25/x
3. Step 3: Cross multiply
   91.83x = 137.76 × 77.25
4. Step 4: Simplify right side
   91.83x = 10,641.96
5. Step 5: Solve for x
   x = 10,641.96/91.83
6. Step 6: Final answer
   x = 115.89