Finding the Fourth Proportional to 1,001.98, 1,380.06 and 780.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,001.98 : 1,380.06 = 780.45 : x
2. Step 2: Convert to fraction form
   1,001.98/1,380.06 = 780.45/x
3. Step 3: Cross multiply
   1,001.98x = 1,380.06 × 780.45
4. Step 4: Simplify right side
   1,001.98x = 1,077,067.83
5. Step 5: Solve for x
   x = 1,077,067.83/1,001.98
6. Step 6: Final answer
   x = 1,074.94