Finding the Fourth Proportional to 1,990.72, 2,986.56 and 692.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,990.72 : 2,986.56 = 692.16 : x
2. Step 2: Convert to fraction form
   1,990.72/2,986.56 = 692.16/x
3. Step 3: Cross multiply
   1,990.72x = 2,986.56 × 692.16
4. Step 4: Simplify right side
   1,990.72x = 2,067,177.37
5. Step 5: Solve for x
   x = 2,067,177.37/1,990.72
6. Step 6: Final answer
   x = 1,038.41