Finding the Fourth Proportional to 2,111.64, 3,165.50 and 812.84

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.64 : 3,165.50 = 812.84 : x
2. Step 2: Convert to fraction form
   2,111.64/3,165.50 = 812.84/x
3. Step 3: Cross multiply
   2,111.64x = 3,165.50 × 812.84
4. Step 4: Simplify right side
   2,111.64x = 2,573,045.02
5. Step 5: Solve for x
   x = 2,573,045.02/2,111.64
6. Step 6: Final answer
   x = 1,218.51