Finding the Fourth Proportional to 2,011.86, 3,019.01 and 780.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,011.86 : 3,019.01 = 780.39 : x
2. Step 2: Convert to fraction form
   2,011.86/3,019.01 = 780.39/x
3. Step 3: Cross multiply
   2,011.86x = 3,019.01 × 780.39
4. Step 4: Simplify right side
   2,011.86x = 2,356,001.31
5. Step 5: Solve for x
   x = 2,356,001.31/2,011.86
6. Step 6: Final answer
   x = 1,171.06