Finding the Fourth Proportional to 12,111, 18,173.79 and 5,185.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,111 : 18,173.79 = 5,185.50 : x
2. Step 2: Convert to fraction form
   12,111/18,173.79 = 5,185.50/x
3. Step 3: Cross multiply
   12,111x = 18,173.79 × 5,185.50
4. Step 4: Simplify right side
   12,111x = 94,240,188.05
5. Step 5: Solve for x
   x = 94,240,188.05/12,111
6. Step 6: Final answer
   x = 7,781.37