Finding the Fourth Proportional to 1,380.33, 1,905.11 and 790.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.33 : 1,905.11 = 790.86 : x
2. Step 2: Convert to fraction form
   1,380.33/1,905.11 = 790.86/x
3. Step 3: Cross multiply
   1,380.33x = 1,905.11 × 790.86
4. Step 4: Simplify right side
   1,380.33x = 1,506,680.34
5. Step 5: Solve for x
   x = 1,506,680.34/1,380.33
6. Step 6: Final answer
   x = 1,091.54