Finding the Fourth Proportional to 21,667.41, 29,909.63 and 13,598.90

Step by Step Solution

1. Step 1: Write the proportion equation
   21,667.41 : 29,909.63 = 13,598.90 : x
2. Step 2: Convert to fraction form
   21,667.41/29,909.63 = 13,598.90/x
3. Step 3: Cross multiply
   21,667.41x = 29,909.63 × 13,598.90
4. Step 4: Simplify right side
   21,667.41x = 406,737,849.86
5. Step 5: Solve for x
   x = 406,737,849.86/21,667.41
6. Step 6: Final answer
   x = 18,771.88