Finding the Fourth Proportional to 1,659.75, 2,290.09 and 987.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,659.75 : 2,290.09 = 987.78 : x
2. Step 2: Convert to fraction form
   1,659.75/2,290.09 = 987.78/x
3. Step 3: Cross multiply
   1,659.75x = 2,290.09 × 987.78
4. Step 4: Simplify right side
   1,659.75x = 2,262,105.10
5. Step 5: Solve for x
   x = 2,262,105.10/1,659.75
6. Step 6: Final answer
   x = 1,362.92