Finding the Fourth Proportional to 1,527.80, 2,109.12 and 990.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,527.80 : 2,109.12 = 990.07 : x
2. Step 2: Convert to fraction form
   1,527.80/2,109.12 = 990.07/x
3. Step 3: Cross multiply
   1,527.80x = 2,109.12 × 990.07
4. Step 4: Simplify right side
   1,527.80x = 2,088,184.89
5. Step 5: Solve for x
   x = 2,088,184.89/1,527.80
6. Step 6: Final answer
   x = 1,366.80