Finding the Fourth Proportional to 1,776.74, 2,451.89 and 990.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,776.74 : 2,451.89 = 990.80 : x
2. Step 2: Convert to fraction form
   1,776.74/2,451.89 = 990.80/x
3. Step 3: Cross multiply
   1,776.74x = 2,451.89 × 990.80
4. Step 4: Simplify right side
   1,776.74x = 2,429,322.83
5. Step 5: Solve for x
   x = 2,429,322.83/1,776.74
6. Step 6: Final answer
   x = 1,367.29