Finding the Fourth Proportional to 1,370.34, 1,890.61 and 780.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.34 : 1,890.61 = 780.46 : x
2. Step 2: Convert to fraction form
   1,370.34/1,890.61 = 780.46/x
3. Step 3: Cross multiply
   1,370.34x = 1,890.61 × 780.46
4. Step 4: Simplify right side
   1,370.34x = 1,475,538.80
5. Step 5: Solve for x
   x = 1,475,538.80/1,370.34
6. Step 6: Final answer
   x = 1,076.77