Finding the Fourth Proportional to 1,407.20, 1,941.77 and 777.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.20 : 1,941.77 = 777.69 : x
2. Step 2: Convert to fraction form
   1,407.20/1,941.77 = 777.69/x
3. Step 3: Cross multiply
   1,407.20x = 1,941.77 × 777.69
4. Step 4: Simplify right side
   1,407.20x = 1,510,081.51
5. Step 5: Solve for x
   x = 1,510,081.51/1,407.20
6. Step 6: Final answer
   x = 1,073.11