Finding the Fourth Proportional to 99,820.80, 149,731.20 and 82,106.10

Step by Step Solution

1. Step 1: Write the proportion equation
   99,820.80 : 149,731.20 = 82,106.10 : x
2. Step 2: Convert to fraction form
   99,820.80/149,731.20 = 82,106.10/x
3. Step 3: Cross multiply
   99,820.80x = 149,731.20 × 82,106.10
4. Step 4: Simplify right side
   99,820.80x = 12,293,844,880.32
5. Step 5: Solve for x
   x = 12,293,844,880.32/99,820.80
6. Step 6: Final answer
   x = 123,159.15