Finding the Fourth Proportional to 1,075.45, 1,612.16 and 811.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,075.45 : 1,612.16 = 811.50 : x
2. Step 2: Convert to fraction form
   1,075.45/1,612.16 = 811.50/x
3. Step 3: Cross multiply
   1,075.45x = 1,612.16 × 811.50
4. Step 4: Simplify right side
   1,075.45x = 1,308,259.78
5. Step 5: Solve for x
   x = 1,308,259.78/1,075.45
6. Step 6: Final answer
   x = 1,216.48