Finding the Fourth Proportional to 1,397.68, 1,928.58 and 808.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.68 : 1,928.58 = 808.10 : x
2. Step 2: Convert to fraction form
   1,397.68/1,928.58 = 808.10/x
3. Step 3: Cross multiply
   1,397.68x = 1,928.58 × 808.10
4. Step 4: Simplify right side
   1,397.68x = 1,558,492.30
5. Step 5: Solve for x
   x = 1,558,492.30/1,397.68
6. Step 6: Final answer
   x = 1,115.06