Finding the Fourth Proportional to 1,410.42, 1,946.40 and 780.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,410.42 : 1,946.40 = 780.90 : x
2. Step 2: Convert to fraction form
   1,410.42/1,946.40 = 780.90/x
3. Step 3: Cross multiply
   1,410.42x = 1,946.40 × 780.90
4. Step 4: Simplify right side
   1,410.42x = 1,519,943.76
5. Step 5: Solve for x
   x = 1,519,943.76/1,410.42
6. Step 6: Final answer
   x = 1,077.65