Finding the Fourth Proportional to 1,530.30, 2,111.78 and 900.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,530.30 : 2,111.78 = 900.90 : x
2. Step 2: Convert to fraction form
   1,530.30/2,111.78 = 900.90/x
3. Step 3: Cross multiply
   1,530.30x = 2,111.78 × 900.90
4. Step 4: Simplify right side
   1,530.30x = 1,902,498.10
5. Step 5: Solve for x
   x = 1,902,498.10/1,530.30
6. Step 6: Final answer
   x = 1,243.22