Finding the Fourth Proportional to 99.05, 148.41 and 71.91

Step by Step Solution

1. Step 1: Write the proportion equation
   99.05 : 148.41 = 71.91 : x
2. Step 2: Convert to fraction form
   99.05/148.41 = 71.91/x
3. Step 3: Cross multiply
   99.05x = 148.41 × 71.91
4. Step 4: Simplify right side
   99.05x = 10,672.16
5. Step 5: Solve for x
   x = 10,672.16/99.05
6. Step 6: Final answer
   x = 107.75