Finding the Fourth Proportional to 2,770.10, 4,155.56 and 991.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,770.10 : 4,155.56 = 991.02 : x
2. Step 2: Convert to fraction form
   2,770.10/4,155.56 = 991.02/x
3. Step 3: Cross multiply
   2,770.10x = 4,155.56 × 991.02
4. Step 4: Simplify right side
   2,770.10x = 4,118,245.55
5. Step 5: Solve for x
   x = 4,118,245.55/2,770.10
6. Step 6: Final answer
   x = 1,486.68