Finding the Fourth Proportional to 1,875.89, 2,814.60 and 780.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,875.89 : 2,814.60 = 780.05 : x
2. Step 2: Convert to fraction form
   1,875.89/2,814.60 = 780.05/x
3. Step 3: Cross multiply
   1,875.89x = 2,814.60 × 780.05
4. Step 4: Simplify right side
   1,875.89x = 2,195,528.73
5. Step 5: Solve for x
   x = 2,195,528.73/1,875.89
6. Step 6: Final answer
   x = 1,170.39