Finding the Fourth Proportional to 1,386.33, 1,915.43 and 1,211.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.33 : 1,915.43 = 1,211.37 : x
2. Step 2: Convert to fraction form
   1,386.33/1,915.43 = 1,211.37/x
3. Step 3: Cross multiply
   1,386.33x = 1,915.43 × 1,211.37
4. Step 4: Simplify right side
   1,386.33x = 2,320,288.38
5. Step 5: Solve for x
   x = 2,320,288.38/1,386.33
6. Step 6: Final answer
   x = 1,673.69