Finding the Fourth Proportional to 12,890.01, 17,796.78 and 9,900.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,890.01 : 17,796.78 = 9,900.50 : x
2. Step 2: Convert to fraction form
   12,890.01/17,796.78 = 9,900.50/x
3. Step 3: Cross multiply
   12,890.01x = 17,796.78 × 9,900.50
4. Step 4: Simplify right side
   12,890.01x = 176,196,931.41
5. Step 5: Solve for x
   x = 176,196,931.41/12,890.01
6. Step 6: Final answer
   x = 13,669.26