Finding the Fourth Proportional to 10,128.51, 13,980.33 and 5,880.60

Step by Step Solution

1. Step 1: Write the proportion equation
   10,128.51 : 13,980.33 = 5,880.60 : x
2. Step 2: Convert to fraction form
   10,128.51/13,980.33 = 5,880.60/x
3. Step 3: Cross multiply
   10,128.51x = 13,980.33 × 5,880.60
4. Step 4: Simplify right side
   10,128.51x = 82,212,728.60
5. Step 5: Solve for x
   x = 82,212,728.60/10,128.51
6. Step 6: Final answer
   x = 8,116.96