Finding the Fourth Proportional to 21,011.82, 28,991.24 and 13,840.98

Step by Step Solution

1. Step 1: Write the proportion equation
   21,011.82 : 28,991.24 = 13,840.98 : x
2. Step 2: Convert to fraction form
   21,011.82/28,991.24 = 13,840.98/x
3. Step 3: Cross multiply
   21,011.82x = 28,991.24 × 13,840.98
4. Step 4: Simplify right side
   21,011.82x = 401,267,173.02
5. Step 5: Solve for x
   x = 401,267,173.02/21,011.82
6. Step 6: Final answer
   x = 19,097.21