Finding the Fourth Proportional to 1,061.83, 1,590.27 and 816.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.83 : 1,590.27 = 816.40 : x
2. Step 2: Convert to fraction form
   1,061.83/1,590.27 = 816.40/x
3. Step 3: Cross multiply
   1,061.83x = 1,590.27 × 816.40
4. Step 4: Simplify right side
   1,061.83x = 1,298,296.43
5. Step 5: Solve for x
   x = 1,298,296.43/1,061.83
6. Step 6: Final answer
   x = 1,222.70