Finding the Fourth Proportional to 99.48, 137.04 and 78.72

Step by Step Solution

1. Step 1: Write the proportion equation
   99.48 : 137.04 = 78.72 : x
2. Step 2: Convert to fraction form
   99.48/137.04 = 78.72/x
3. Step 3: Cross multiply
   99.48x = 137.04 × 78.72
4. Step 4: Simplify right side
   99.48x = 10,788.19
5. Step 5: Solve for x
   x = 10,788.19/99.48
6. Step 6: Final answer
   x = 108.45