Finding the Fourth Proportional to 1,389.67, 2,085.12 and 740.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.67 : 2,085.12 = 740.25 : x
2. Step 2: Convert to fraction form
   1,389.67/2,085.12 = 740.25/x
3. Step 3: Cross multiply
   1,389.67x = 2,085.12 × 740.25
4. Step 4: Simplify right side
   1,389.67x = 1,543,510.08
5. Step 5: Solve for x
   x = 1,543,510.08/1,389.67
6. Step 6: Final answer
   x = 1,110.70