Finding the Fourth Proportional to 1,530.22, 2,111.72 and 831.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,530.22 : 2,111.72 = 831.60 : x
2. Step 2: Convert to fraction form
   1,530.22/2,111.72 = 831.60/x
3. Step 3: Cross multiply
   1,530.22x = 2,111.72 × 831.60
4. Step 4: Simplify right side
   1,530.22x = 1,756,095.79
5. Step 5: Solve for x
   x = 1,756,095.79/1,530.22
6. Step 6: Final answer
   x = 1,147.61