Finding the Fourth Proportional to 1,128.15, 1,691.70 and 608.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.15 : 1,691.70 = 608.03 : x
2. Step 2: Convert to fraction form
   1,128.15/1,691.70 = 608.03/x
3. Step 3: Cross multiply
   1,128.15x = 1,691.70 × 608.03
4. Step 4: Simplify right side
   1,128.15x = 1,028,595.89
5. Step 5: Solve for x
   x = 1,028,595.89/1,128.15
6. Step 6: Final answer
   x = 911.75