Finding the Fourth Proportional to 1,387.18, 1,914.30 and 797.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.18 : 1,914.30 = 797.72 : x
2. Step 2: Convert to fraction form
   1,387.18/1,914.30 = 797.72/x
3. Step 3: Cross multiply
   1,387.18x = 1,914.30 × 797.72
4. Step 4: Simplify right side
   1,387.18x = 1,527,075.40
5. Step 5: Solve for x
   x = 1,527,075.40/1,387.18
6. Step 6: Final answer
   x = 1,100.85