Finding the Fourth Proportional to 1,561.39, 2,340.62 and 820.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.39 : 2,340.62 = 820.84 : x
2. Step 2: Convert to fraction form
   1,561.39/2,340.62 = 820.84/x
3. Step 3: Cross multiply
   1,561.39x = 2,340.62 × 820.84
4. Step 4: Simplify right side
   1,561.39x = 1,921,274.52
5. Step 5: Solve for x
   x = 1,921,274.52/1,561.39
6. Step 6: Final answer
   x = 1,230.49