Finding the Fourth Proportional to 2,938.79, 4,408.49 and 991.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,938.79 : 4,408.49 = 991.15 : x
2. Step 2: Convert to fraction form
   2,938.79/4,408.49 = 991.15/x
3. Step 3: Cross multiply
   2,938.79x = 4,408.49 × 991.15
4. Step 4: Simplify right side
   2,938.79x = 4,369,466.32
5. Step 5: Solve for x
   x = 4,369,466.32/2,938.79
6. Step 6: Final answer
   x = 1,486.82