Finding the Fourth Proportional to 2,780.72, 4,172.22 and 1,219.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,780.72 : 4,172.22 = 1,219.92 : x
2. Step 2: Convert to fraction form
   2,780.72/4,172.22 = 1,219.92/x
3. Step 3: Cross multiply
   2,780.72x = 4,172.22 × 1,219.92
4. Step 4: Simplify right side
   2,780.72x = 5,089,774.62
5. Step 5: Solve for x
   x = 5,089,774.62/2,780.72
6. Step 6: Final answer
   x = 1,830.38