Finding the Fourth Proportional to 2,111.51, 3,165.43 and 812.13

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.51 : 3,165.43 = 812.13 : x
2. Step 2: Convert to fraction form
   2,111.51/3,165.43 = 812.13/x
3. Step 3: Cross multiply
   2,111.51x = 3,165.43 × 812.13
4. Step 4: Simplify right side
   2,111.51x = 2,570,740.67
5. Step 5: Solve for x
   x = 2,570,740.67/2,111.51
6. Step 6: Final answer
   x = 1,217.49