Finding the Fourth Proportional to 2,990.72, 4,479.12 and 2,886.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,990.72 : 4,479.12 = 2,886.90 : x
2. Step 2: Convert to fraction form
   2,990.72/4,479.12 = 2,886.90/x
3. Step 3: Cross multiply
   2,990.72x = 4,479.12 × 2,886.90
4. Step 4: Simplify right side
   2,990.72x = 12,930,771.53
5. Step 5: Solve for x
   x = 12,930,771.53/2,990.72
6. Step 6: Final answer
   x = 4,323.63