Finding the Fourth Proportional to 2,061.65, 3,091.70 and 828.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,061.65 : 3,091.70 = 828.64 : x
2. Step 2: Convert to fraction form
   2,061.65/3,091.70 = 828.64/x
3. Step 3: Cross multiply
   2,061.65x = 3,091.70 × 828.64
4. Step 4: Simplify right side
   2,061.65x = 2,561,912.22
5. Step 5: Solve for x
   x = 2,561,912.22/2,061.65
6. Step 6: Final answer
   x = 1,242.65