Finding the Fourth Proportional to 1,158.78, 1,598.88 and 661.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,158.78 : 1,598.88 = 661.29 : x
2. Step 2: Convert to fraction form
   1,158.78/1,598.88 = 661.29/x
3. Step 3: Cross multiply
   1,158.78x = 1,598.88 × 661.29
4. Step 4: Simplify right side
   1,158.78x = 1,057,323.36
5. Step 5: Solve for x
   x = 1,057,323.36/1,158.78
6. Step 6: Final answer
   x = 912.45