Finding the Fourth Proportional to 99.98, 149.76 and 72.88

Step by Step Solution

1. Step 1: Write the proportion equation
   99.98 : 149.76 = 72.88 : x
2. Step 2: Convert to fraction form
   99.98/149.76 = 72.88/x
3. Step 3: Cross multiply
   99.98x = 149.76 × 72.88
4. Step 4: Simplify right side
   99.98x = 10,914.51
5. Step 5: Solve for x
   x = 10,914.51/99.98
6. Step 6: Final answer
   x = 109.17