Finding the Fourth Proportional to 1,370.00, 1,890.56 and 780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.00 : 1,890.56 = 780.50 : x
2. Step 2: Convert to fraction form
   1,370.00/1,890.56 = 780.50/x
3. Step 3: Cross multiply
   1,370.00x = 1,890.56 × 780.50
4. Step 4: Simplify right side
   1,370.00x = 1,475,568.72
5. Step 5: Solve for x
   x = 1,475,568.72/1,370.00
6. Step 6: Final answer
   x = 1,077.06