Finding the Fourth Proportional to 31,116.21, 42,938.68 and 17,685.60

Step by Step Solution

1. Step 1: Write the proportion equation
   31,116.21 : 42,938.68 = 17,685.60 : x
2. Step 2: Convert to fraction form
   31,116.21/42,938.68 = 17,685.60/x
3. Step 3: Cross multiply
   31,116.21x = 42,938.68 × 17,685.60
4. Step 4: Simplify right side
   31,116.21x = 759,396,319.01
5. Step 5: Solve for x
   x = 759,396,319.01/31,116.21
6. Step 6: Final answer
   x = 24,405.17