Finding the Fourth Proportional to 31,158.61, 42,998.72 and 19,221.91

Step by Step Solution

1. Step 1: Write the proportion equation
   31,158.61 : 42,998.72 = 19,221.91 : x
2. Step 2: Convert to fraction form
   31,158.61/42,998.72 = 19,221.91/x
3. Step 3: Cross multiply
   31,158.61x = 42,998.72 × 19,221.91
4. Step 4: Simplify right side
   31,158.61x = 826,517,322.35
5. Step 5: Solve for x
   x = 826,517,322.35/31,158.61
6. Step 6: Final answer
   x = 26,526.13