Finding the Fourth Proportional to 1,407.81, 1,942.79 and 786.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.81 : 1,942.79 = 786.81 : x
2. Step 2: Convert to fraction form
   1,407.81/1,942.79 = 786.81/x
3. Step 3: Cross multiply
   1,407.81x = 1,942.79 × 786.81
4. Step 4: Simplify right side
   1,407.81x = 1,528,606.60
5. Step 5: Solve for x
   x = 1,528,606.60/1,407.81
6. Step 6: Final answer
   x = 1,085.80