Finding the Fourth Proportional to 2,012.72, 3,019.42 and 780.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,012.72 : 3,019.42 = 780.02 : x
2. Step 2: Convert to fraction form
   2,012.72/3,019.42 = 780.02/x
3. Step 3: Cross multiply
   2,012.72x = 3,019.42 × 780.02
4. Step 4: Simplify right side
   2,012.72x = 2,355,207.99
5. Step 5: Solve for x
   x = 2,355,207.99/2,012.72
6. Step 6: Final answer
   x = 1,170.16