Finding the Fourth Proportional to 99.86, 149.51 and 72.86

Step by Step Solution

1. Step 1: Write the proportion equation
   99.86 : 149.51 = 72.86 : x
2. Step 2: Convert to fraction form
   99.86/149.51 = 72.86/x
3. Step 3: Cross multiply
   99.86x = 149.51 × 72.86
4. Step 4: Simplify right side
   99.86x = 10,892.73
5. Step 5: Solve for x
   x = 10,892.73/99.86
6. Step 6: Final answer
   x = 109.09