Finding the Fourth Proportional to 1,438.80, 1,985.10 and 849.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.80 : 1,985.10 = 849.30 : x
2. Step 2: Convert to fraction form
   1,438.80/1,985.10 = 849.30/x
3. Step 3: Cross multiply
   1,438.80x = 1,985.10 × 849.30
4. Step 4: Simplify right side
   1,438.80x = 1,685,945.43
5. Step 5: Solve for x
   x = 1,685,945.43/1,438.80
6. Step 6: Final answer
   x = 1,171.77