Finding the Fourth Proportional to 99.69, 137.49 and 78.93

Step by Step Solution

1. Step 1: Write the proportion equation
   99.69 : 137.49 = 78.93 : x
2. Step 2: Convert to fraction form
   99.69/137.49 = 78.93/x
3. Step 3: Cross multiply
   99.69x = 137.49 × 78.93
4. Step 4: Simplify right side
   99.69x = 10,852.09
5. Step 5: Solve for x
   x = 10,852.09/99.69
6. Step 6: Final answer
   x = 108.86