Finding the Fourth Proportional to 1,356.55, 1,871.99 and 767.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.55 : 1,871.99 = 767.21 : x
2. Step 2: Convert to fraction form
   1,356.55/1,871.99 = 767.21/x
3. Step 3: Cross multiply
   1,356.55x = 1,871.99 × 767.21
4. Step 4: Simplify right side
   1,356.55x = 1,436,200.93
5. Step 5: Solve for x
   x = 1,436,200.93/1,356.55
6. Step 6: Final answer
   x = 1,058.72