Finding the Fourth Proportional to 99.10, 148.75 and 72.10

Step by Step Solution

1. Step 1: Write the proportion equation
   99.10 : 148.75 = 72.10 : x
2. Step 2: Convert to fraction form
   99.10/148.75 = 72.10/x
3. Step 3: Cross multiply
   99.10x = 148.75 × 72.10
4. Step 4: Simplify right side
   99.10x = 10,723.77
5. Step 5: Solve for x
   x = 10,723.77/99.10
6. Step 6: Final answer
   x = 108.22