Finding the Fourth Proportional to 1,530.18, 2,111.70 and 831.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,530.18 : 2,111.70 = 831.57 : x
2. Step 2: Convert to fraction form
   1,530.18/2,111.70 = 831.57/x
3. Step 3: Cross multiply
   1,530.18x = 2,111.70 × 831.57
4. Step 4: Simplify right side
   1,530.18x = 1,756,026.37
5. Step 5: Solve for x
   x = 1,756,026.37/1,530.18
6. Step 6: Final answer
   x = 1,147.59