Finding the Fourth Proportional to 11,128.39, 15,331.34 and 7,722.14

Step by Step Solution

1. Step 1: Write the proportion equation
   11,128.39 : 15,331.34 = 7,722.14 : x
2. Step 2: Convert to fraction form
   11,128.39/15,331.34 = 7,722.14/x
3. Step 3: Cross multiply
   11,128.39x = 15,331.34 × 7,722.14
4. Step 4: Simplify right side
   11,128.39x = 118,390,696.52
5. Step 5: Solve for x
   x = 118,390,696.52/11,128.39
6. Step 6: Final answer
   x = 10,638.62