Finding the Fourth Proportional to 1,123.19, 1,681.54 and 938.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.19 : 1,681.54 = 938.51 : x
2. Step 2: Convert to fraction form
   1,123.19/1,681.54 = 938.51/x
3. Step 3: Cross multiply
   1,123.19x = 1,681.54 × 938.51
4. Step 4: Simplify right side
   1,123.19x = 1,578,131.35
5. Step 5: Solve for x
   x = 1,578,131.35/1,123.19
6. Step 6: Final answer
   x = 1,405.05