Finding the Fourth Proportional to 1,145.91, 1,581.50 and 680.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.91 : 1,581.50 = 680.19 : x
2. Step 2: Convert to fraction form
   1,145.91/1,581.50 = 680.19/x
3. Step 3: Cross multiply
   1,145.91x = 1,581.50 × 680.19
4. Step 4: Simplify right side
   1,145.91x = 1,075,714.28
5. Step 5: Solve for x
   x = 1,075,714.28/1,145.91
6. Step 6: Final answer
   x = 938.75