Finding the Fourth Proportional to 1,389.34, 1,917.30 and 799.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.34 : 1,917.30 = 799.84 : x
2. Step 2: Convert to fraction form
   1,389.34/1,917.30 = 799.84/x
3. Step 3: Cross multiply
   1,389.34x = 1,917.30 × 799.84
4. Step 4: Simplify right side
   1,389.34x = 1,533,533.23
5. Step 5: Solve for x
   x = 1,533,533.23/1,389.34
6. Step 6: Final answer
   x = 1,103.79