Finding the Fourth Proportional to 2,085.72, 3,126.96 and 991.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.72 : 3,126.96 = 991.42 : x
2. Step 2: Convert to fraction form
   2,085.72/3,126.96 = 991.42/x
3. Step 3: Cross multiply
   2,085.72x = 3,126.96 × 991.42
4. Step 4: Simplify right side
   2,085.72x = 3,100,130.68
5. Step 5: Solve for x
   x = 3,100,130.68/2,085.72
6. Step 6: Final answer
   x = 1,486.36