Finding the Fourth Proportional to 1,820.42, 2,728.68 and 780.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,820.42 : 2,728.68 = 780.26 : x
2. Step 2: Convert to fraction form
   1,820.42/2,728.68 = 780.26/x
3. Step 3: Cross multiply
   1,820.42x = 2,728.68 × 780.26
4. Step 4: Simplify right side
   1,820.42x = 2,129,079.86
5. Step 5: Solve for x
   x = 2,129,079.86/1,820.42
6. Step 6: Final answer
   x = 1,169.55