Finding the Fourth Proportional to 11,397.42, 17,111.88 and 7,878.78

Step by Step Solution

1. Step 1: Write the proportion equation
   11,397.42 : 17,111.88 = 7,878.78 : x
2. Step 2: Convert to fraction form
   11,397.42/17,111.88 = 7,878.78/x
3. Step 3: Cross multiply
   11,397.42x = 17,111.88 × 7,878.78
4. Step 4: Simplify right side
   11,397.42x = 134,820,737.91
5. Step 5: Solve for x
   x = 134,820,737.91/11,397.42
6. Step 6: Final answer
   x = 11,829.06