Finding the Fourth Proportional to 1,189.40, 1,780.43 and 930.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.40 : 1,780.43 = 930.15 : x
2. Step 2: Convert to fraction form
   1,189.40/1,780.43 = 930.15/x
3. Step 3: Cross multiply
   1,189.40x = 1,780.43 × 930.15
4. Step 4: Simplify right side
   1,189.40x = 1,656,062.31
5. Step 5: Solve for x
   x = 1,656,062.31/1,189.40
6. Step 6: Final answer
   x = 1,392.36