Finding the Fourth Proportional to 1,370.07, 1,890.72 and 780.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.07 : 1,890.72 = 780.62 : x
2. Step 2: Convert to fraction form
   1,370.07/1,890.72 = 780.62/x
3. Step 3: Cross multiply
   1,370.07x = 1,890.72 × 780.62
4. Step 4: Simplify right side
   1,370.07x = 1,475,924.39
5. Step 5: Solve for x
   x = 1,475,924.39/1,370.07
6. Step 6: Final answer
   x = 1,077.26