Finding the Fourth Proportional to 11,700.51, 17,540.82 and 5,121.78

Step by Step Solution

1. Step 1: Write the proportion equation
   11,700.51 : 17,540.82 = 5,121.78 : x
2. Step 2: Convert to fraction form
   11,700.51/17,540.82 = 5,121.78/x
3. Step 3: Cross multiply
   11,700.51x = 17,540.82 × 5,121.78
4. Step 4: Simplify right side
   11,700.51x = 89,840,221.06
5. Step 5: Solve for x
   x = 89,840,221.06/11,700.51
6. Step 6: Final answer
   x = 7,678.32