Finding the Fourth Proportional to 9,139.51, 12,611.82 and 5,160.97

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.51 : 12,611.82 = 5,160.97 : x
2. Step 2: Convert to fraction form
   9,139.51/12,611.82 = 5,160.97/x
3. Step 3: Cross multiply
   9,139.51x = 12,611.82 × 5,160.97
4. Step 4: Simplify right side
   9,139.51x = 65,089,224.67
5. Step 5: Solve for x
   x = 65,089,224.67/9,139.51
6. Step 6: Final answer
   x = 7,121.74