Finding the Fourth Proportional to 11,561.61, 17,405.42 and 7,886.99

Step by Step Solution

1. Step 1: Write the proportion equation
   11,561.61 : 17,405.42 = 7,886.99 : x
2. Step 2: Convert to fraction form
   11,561.61/17,405.42 = 7,886.99/x
3. Step 3: Cross multiply
   11,561.61x = 17,405.42 × 7,886.99
4. Step 4: Simplify right side
   11,561.61x = 137,276,247.02
5. Step 5: Solve for x
   x = 137,276,247.02/11,561.61
6. Step 6: Final answer
   x = 11,873.45