Finding the Fourth Proportional to 22,916, 31,619.28 and 13,485.60

Step by Step Solution

1. Step 1: Write the proportion equation
   22,916 : 31,619.28 = 13,485.60 : x
2. Step 2: Convert to fraction form
   22,916/31,619.28 = 13,485.60/x
3. Step 3: Cross multiply
   22,916x = 31,619.28 × 13,485.60
4. Step 4: Simplify right side
   22,916x = 426,404,962.37
5. Step 5: Solve for x
   x = 426,404,962.37/22,916
6. Step 6: Final answer
   x = 18,607.30