Finding the Fourth Proportional to 91,681.10, 136,894.42 and 82,131.80

Step by Step Solution

1. Step 1: Write the proportion equation
   91,681.10 : 136,894.42 = 82,131.80 : x
2. Step 2: Convert to fraction form
   91,681.10/136,894.42 = 82,131.80/x
3. Step 3: Cross multiply
   91,681.10x = 136,894.42 × 82,131.80
4. Step 4: Simplify right side
   91,681.10x = 11,243,385,124.56
5. Step 5: Solve for x
   x = 11,243,385,124.56/91,681.10
6. Step 6: Final answer
   x = 122,635.80