Finding the Fourth Proportional to 1,428.75, 1,971.71 and 799.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.75 : 1,971.71 = 799.30 : x
2. Step 2: Convert to fraction form
   1,428.75/1,971.71 = 799.30/x
3. Step 3: Cross multiply
   1,428.75x = 1,971.71 × 799.30
4. Step 4: Simplify right side
   1,428.75x = 1,575,973.95
5. Step 5: Solve for x
   x = 1,575,973.95/1,428.75
6. Step 6: Final answer
   x = 1,103.05