Finding the Fourth Proportional to 1,361.61, 1,878.90 and 772.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.61 : 1,878.90 = 772.18 : x
2. Step 2: Convert to fraction form
   1,361.61/1,878.90 = 772.18/x
3. Step 3: Cross multiply
   1,361.61x = 1,878.90 × 772.18
4. Step 4: Simplify right side
   1,361.61x = 1,450,851.98
5. Step 5: Solve for x
   x = 1,450,851.98/1,361.61
6. Step 6: Final answer
   x = 1,065.54