Finding the Fourth Proportional to 2,109.98, 3,166.05 and 812.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.98 : 3,166.05 = 812.30 : x
2. Step 2: Convert to fraction form
   2,109.98/3,166.05 = 812.30/x
3. Step 3: Cross multiply
   2,109.98x = 3,166.05 × 812.30
4. Step 4: Simplify right side
   2,109.98x = 2,571,782.42
5. Step 5: Solve for x
   x = 2,571,782.42/2,109.98
6. Step 6: Final answer
   x = 1,218.87