Finding the Fourth Proportional to 1,528.88, 2,109.85 and 830.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.88 : 2,109.85 = 830.25 : x
2. Step 2: Convert to fraction form
   1,528.88/2,109.85 = 830.25/x
3. Step 3: Cross multiply
   1,528.88x = 2,109.85 × 830.25
4. Step 4: Simplify right side
   1,528.88x = 1,751,700.89
5. Step 5: Solve for x
   x = 1,751,700.89/1,528.88
6. Step 6: Final answer
   x = 1,145.75