Finding the Fourth Proportional to 1,387.35, 1,914.56 and 828.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.35 : 1,914.56 = 828.08 : x
2. Step 2: Convert to fraction form
   1,387.35/1,914.56 = 828.08/x
3. Step 3: Cross multiply
   1,387.35x = 1,914.56 × 828.08
4. Step 4: Simplify right side
   1,387.35x = 1,585,401.34
5. Step 5: Solve for x
   x = 1,585,401.34/1,387.35
6. Step 6: Final answer
   x = 1,142.76