Finding the Fourth Proportional to 1,145.78, 1,581.33 and 680.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.78 : 1,581.33 = 680.06 : x
2. Step 2: Convert to fraction form
   1,145.78/1,581.33 = 680.06/x
3. Step 3: Cross multiply
   1,145.78x = 1,581.33 × 680.06
4. Step 4: Simplify right side
   1,145.78x = 1,075,399.28
5. Step 5: Solve for x
   x = 1,075,399.28/1,145.78
6. Step 6: Final answer
   x = 938.57