Finding the Fourth Proportional to 1,387.37, 1,914.91 and 1,072.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.37 : 1,914.91 = 1,072.16 : x
2. Step 2: Convert to fraction form
   1,387.37/1,914.91 = 1,072.16/x
3. Step 3: Cross multiply
   1,387.37x = 1,914.91 × 1,072.16
4. Step 4: Simplify right side
   1,387.37x = 2,053,077.65
5. Step 5: Solve for x
   x = 2,053,077.65/1,387.37
6. Step 6: Final answer
   x = 1,479.83