Finding the Fourth Proportional to 99,630.48, 148,810.75 and 90,128.18

Step by Step Solution

1. Step 1: Write the proportion equation
   99,630.48 : 148,810.75 = 90,128.18 : x
2. Step 2: Convert to fraction form
   99,630.48/148,810.75 = 90,128.18/x
3. Step 3: Cross multiply
   99,630.48x = 148,810.75 × 90,128.18
4. Step 4: Simplify right side
   99,630.48x = 13,412,041,092.56
5. Step 5: Solve for x
   x = 13,412,041,092.56/99,630.48
6. Step 6: Final answer
   x = 134,617.86