Finding the Fourth Proportional to 10,128.89, 13,972.54 and 8,242.58

Step by Step Solution

1. Step 1: Write the proportion equation
   10,128.89 : 13,972.54 = 8,242.58 : x
2. Step 2: Convert to fraction form
   10,128.89/13,972.54 = 8,242.58/x
3. Step 3: Cross multiply
   10,128.89x = 13,972.54 × 8,242.58
4. Step 4: Simplify right side
   10,128.89x = 115,169,778.75
5. Step 5: Solve for x
   x = 115,169,778.75/10,128.89
6. Step 6: Final answer
   x = 11,370.42