Finding the Fourth Proportional to 1,380.72, 2,070.76 and 885.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.72 : 2,070.76 = 885.63 : x
2. Step 2: Convert to fraction form
   1,380.72/2,070.76 = 885.63/x
3. Step 3: Cross multiply
   1,380.72x = 2,070.76 × 885.63
4. Step 4: Simplify right side
   1,380.72x = 1,833,924.96
5. Step 5: Solve for x
   x = 1,833,924.96/1,380.72
6. Step 6: Final answer
   x = 1,328.24