Finding the Fourth Proportional to 99.85, 137.89 and 91.52

Step by Step Solution

1. Step 1: Write the proportion equation
   99.85 : 137.89 = 91.52 : x
2. Step 2: Convert to fraction form
   99.85/137.89 = 91.52/x
3. Step 3: Cross multiply
   99.85x = 137.89 × 91.52
4. Step 4: Simplify right side
   99.85x = 12,619.69
5. Step 5: Solve for x
   x = 12,619.69/99.85
6. Step 6: Final answer
   x = 126.39