Finding the Fourth Proportional to 17,870.79, 26,785.53 and 13,120.14

Step by Step Solution

1. Step 1: Write the proportion equation
   17,870.79 : 26,785.53 = 13,120.14 : x
2. Step 2: Convert to fraction form
   17,870.79/26,785.53 = 13,120.14/x
3. Step 3: Cross multiply
   17,870.79x = 26,785.53 × 13,120.14
4. Step 4: Simplify right side
   17,870.79x = 351,429,903.57
5. Step 5: Solve for x
   x = 351,429,903.57/17,870.79
6. Step 6: Final answer
   x = 19,665.05