Finding the Fourth Proportional to 28,091.76, 42,149.94 and 13,311.24

Step by Step Solution

1. Step 1: Write the proportion equation
   28,091.76 : 42,149.94 = 13,311.24 : x
2. Step 2: Convert to fraction form
   28,091.76/42,149.94 = 13,311.24/x
3. Step 3: Cross multiply
   28,091.76x = 42,149.94 × 13,311.24
4. Step 4: Simplify right side
   28,091.76x = 561,067,967.33
5. Step 5: Solve for x
   x = 561,067,967.33/28,091.76
6. Step 6: Final answer
   x = 19,972.69