Finding the Fourth Proportional to 1,409.90, 1,945.46 and 812.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,409.90 : 1,945.46 = 812.30 : x
2. Step 2: Convert to fraction form
   1,409.90/1,945.46 = 812.30/x
3. Step 3: Cross multiply
   1,409.90x = 1,945.46 × 812.30
4. Step 4: Simplify right side
   1,409.90x = 1,580,283.37
5. Step 5: Solve for x
   x = 1,580,283.37/1,409.90
6. Step 6: Final answer
   x = 1,120.85