Finding the Fourth Proportional to 1,123.60, 1,686.60 and 994.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.60 : 1,686.60 = 994.42 : x
2. Step 2: Convert to fraction form
   1,123.60/1,686.60 = 994.42/x
3. Step 3: Cross multiply
   1,123.60x = 1,686.60 × 994.42
4. Step 4: Simplify right side
   1,123.60x = 1,677,186.29
5. Step 5: Solve for x
   x = 1,677,186.29/1,123.60
6. Step 6: Final answer
   x = 1,492.69