Finding the Fourth Proportional to 99.72, 137.82 and 98.88

Step by Step Solution

1. Step 1: Write the proportion equation
   99.72 : 137.82 = 98.88 : x
2. Step 2: Convert to fraction form
   99.72/137.82 = 98.88/x
3. Step 3: Cross multiply
   99.72x = 137.82 × 98.88
4. Step 4: Simplify right side
   99.72x = 13,627.64
5. Step 5: Solve for x
   x = 13,627.64/99.72
6. Step 6: Final answer
   x = 136.66