Finding the Fourth Proportional to 866.53, 1,300.40 and 789.98

Step by Step Solution

1. Step 1: Write the proportion equation
   866.53 : 1,300.40 = 789.98 : x
2. Step 2: Convert to fraction form
   866.53/1,300.40 = 789.98/x
3. Step 3: Cross multiply
   866.53x = 1,300.40 × 789.98
4. Step 4: Simplify right side
   866.53x = 1,027,286.04
5. Step 5: Solve for x
   x = 1,027,286.04/866.53
6. Step 6: Final answer
   x = 1,185.52