Finding the Fourth Proportional to 1,407.79, 1,942.72 and 778.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.79 : 1,942.72 = 778.34 : x
2. Step 2: Convert to fraction form
   1,407.79/1,942.72 = 778.34/x
3. Step 3: Cross multiply
   1,407.79x = 1,942.72 × 778.34
4. Step 4: Simplify right side
   1,407.79x = 1,512,096.68
5. Step 5: Solve for x
   x = 1,512,096.68/1,407.79
6. Step 6: Final answer
   x = 1,074.09