Finding the Fourth Proportional to 2,061.90, 3,091.60 and 811.00

Step by Step Solution

1. Step 1: Write the proportion equation
   2,061.90 : 3,091.60 = 811.00 : x
2. Step 2: Convert to fraction form
   2,061.90/3,091.60 = 811.00/x
3. Step 3: Cross multiply
   2,061.90x = 3,091.60 × 811.00
4. Step 4: Simplify right side
   2,061.90x = 2,507,292.48
5. Step 5: Solve for x
   x = 2,507,292.48/2,061.90
6. Step 6: Final answer
   x = 1,216.01