Finding the Fourth Proportional to 1,397.49, 1,928.69 and 808

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.49 : 1,928.69 = 808 : x
2. Step 2: Convert to fraction form
   1,397.49/1,928.69 = 808/x
3. Step 3: Cross multiply
   1,397.49x = 1,928.69 × 808
4. Step 4: Simplify right side
   1,397.49x = 1,558,381.52
5. Step 5: Solve for x
   x = 1,558,381.52/1,397.49
6. Step 6: Final answer
   x = 1,115.13