Finding the Fourth Proportional to 1,030.78, 1,422.06 and 637.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,030.78 : 1,422.06 = 637.12 : x
2. Step 2: Convert to fraction form
   1,030.78/1,422.06 = 637.12/x
3. Step 3: Cross multiply
   1,030.78x = 1,422.06 × 637.12
4. Step 4: Simplify right side
   1,030.78x = 906,022.87
5. Step 5: Solve for x
   x = 906,022.87/1,030.78
6. Step 6: Final answer
   x = 878.97