Finding the Fourth Proportional to 1,528.67, 2,109.57 and 890.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,528.67 : 2,109.57 = 890.77 : x
2. Step 2: Convert to fraction form
   1,528.67/2,109.57 = 890.77/x
3. Step 3: Cross multiply
   1,528.67x = 2,109.57 × 890.77
4. Step 4: Simplify right side
   1,528.67x = 1,879,131.12
5. Step 5: Solve for x
   x = 1,879,131.12/1,528.67
6. Step 6: Final answer
   x = 1,229.26