Finding the Fourth Proportional to 1,393.42, 2,088.72 and 777.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.42 : 2,088.72 = 777.40 : x
2. Step 2: Convert to fraction form
   1,393.42/2,088.72 = 777.40/x
3. Step 3: Cross multiply
   1,393.42x = 2,088.72 × 777.40
4. Step 4: Simplify right side
   1,393.42x = 1,623,770.93
5. Step 5: Solve for x
   x = 1,623,770.93/1,393.42
6. Step 6: Final answer
   x = 1,165.31