Finding the Fourth Proportional to 1,378.22, 1,902.10 and 788.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.22 : 1,902.10 = 788.87 : x
2. Step 2: Convert to fraction form
   1,378.22/1,902.10 = 788.87/x
3. Step 3: Cross multiply
   1,378.22x = 1,902.10 × 788.87
4. Step 4: Simplify right side
   1,378.22x = 1,500,500.12
5. Step 5: Solve for x
   x = 1,500,500.12/1,378.22
6. Step 6: Final answer
   x = 1,088.72