Finding the Fourth Proportional to 1,378.72, 1,902.01 and 819.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.72 : 1,902.01 = 819.16 : x
2. Step 2: Convert to fraction form
   1,378.72/1,902.01 = 819.16/x
3. Step 3: Cross multiply
   1,378.72x = 1,902.01 × 819.16
4. Step 4: Simplify right side
   1,378.72x = 1,558,041.60
5. Step 5: Solve for x
   x = 1,558,041.60/1,378.72
6. Step 6: Final answer
   x = 1,130.06