Finding the Fourth Proportional to 1,389.24, 1,917.24 and 799.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.24 : 1,917.24 = 799.88 : x
2. Step 2: Convert to fraction form
   1,389.24/1,917.24 = 799.88/x
3. Step 3: Cross multiply
   1,389.24x = 1,917.24 × 799.88
4. Step 4: Simplify right side
   1,389.24x = 1,533,561.93
5. Step 5: Solve for x
   x = 1,533,561.93/1,389.24
6. Step 6: Final answer
   x = 1,103.89