Finding the Fourth Proportional to 1,680.79, 2,520.43 and 900.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,680.79 : 2,520.43 = 900.67 : x
2. Step 2: Convert to fraction form
   1,680.79/2,520.43 = 900.67/x
3. Step 3: Cross multiply
   1,680.79x = 2,520.43 × 900.67
4. Step 4: Simplify right side
   1,680.79x = 2,270,075.69
5. Step 5: Solve for x
   x = 2,270,075.69/1,680.79
6. Step 6: Final answer
   x = 1,350.60