Finding the Fourth Proportional to 1,085.90, 1,627.91 and 436.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.90 : 1,627.91 = 436.19 : x
2. Step 2: Convert to fraction form
   1,085.90/1,627.91 = 436.19/x
3. Step 3: Cross multiply
   1,085.90x = 1,627.91 × 436.19
4. Step 4: Simplify right side
   1,085.90x = 710,075.88
5. Step 5: Solve for x
   x = 710,075.88/1,085.90
6. Step 6: Final answer
   x = 653.91