Finding the Fourth Proportional to 1,402.11, 2,100.77 and 990.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,402.11 : 2,100.77 = 990.45 : x
2. Step 2: Convert to fraction form
   1,402.11/2,100.77 = 990.45/x
3. Step 3: Cross multiply
   1,402.11x = 2,100.77 × 990.45
4. Step 4: Simplify right side
   1,402.11x = 2,080,702.69
5. Step 5: Solve for x
   x = 2,080,702.69/1,402.11
6. Step 6: Final answer
   x = 1,483.98