Finding the Fourth Proportional to 3,780.78, 5,671.77 and 1,317.06

Step by Step Solution

1. Step 1: Write the proportion equation
   3,780.78 : 5,671.77 = 1,317.06 : x
2. Step 2: Convert to fraction form
   3,780.78/5,671.77 = 1,317.06/x
3. Step 3: Cross multiply
   3,780.78x = 5,671.77 × 1,317.06
4. Step 4: Simplify right side
   3,780.78x = 7,470,061.40
5. Step 5: Solve for x
   x = 7,470,061.40/3,780.78
6. Step 6: Final answer
   x = 1,975.80