Finding the Fourth Proportional to 99,431.42, 137,215.32 and 54,719.42

Step by Step Solution

1. Step 1: Write the proportion equation
   99,431.42 : 137,215.32 = 54,719.42 : x
2. Step 2: Convert to fraction form
   99,431.42/137,215.32 = 54,719.42/x
3. Step 3: Cross multiply
   99,431.42x = 137,215.32 × 54,719.42
4. Step 4: Simplify right side
   99,431.42x = 7,508,342,725.51
5. Step 5: Solve for x
   x = 7,508,342,725.51/99,431.42
6. Step 6: Final answer
   x = 75,512.78