Finding the Fourth Proportional to 1,386.86, 1,913.79 and 797.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.86 : 1,913.79 = 797.40 : x
2. Step 2: Convert to fraction form
   1,386.86/1,913.79 = 797.40/x
3. Step 3: Cross multiply
   1,386.86x = 1,913.79 × 797.40
4. Step 4: Simplify right side
   1,386.86x = 1,526,056.15
5. Step 5: Solve for x
   x = 1,526,056.15/1,386.86
6. Step 6: Final answer
   x = 1,100.37