Finding the Fourth Proportional to 1,385.63, 2,075.78 and 1,091.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.63 : 2,075.78 = 1,091.57 : x
2. Step 2: Convert to fraction form
   1,385.63/2,075.78 = 1,091.57/x
3. Step 3: Cross multiply
   1,385.63x = 2,075.78 × 1,091.57
4. Step 4: Simplify right side
   1,385.63x = 2,265,843.34
5. Step 5: Solve for x
   x = 2,265,843.34/1,385.63
6. Step 6: Final answer
   x = 1,635.25