Finding the Fourth Proportional to 1,427.88, 1,970.28 and 838.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,427.88 : 1,970.28 = 838.30 : x
2. Step 2: Convert to fraction form
   1,427.88/1,970.28 = 838.30/x
3. Step 3: Cross multiply
   1,427.88x = 1,970.28 × 838.30
4. Step 4: Simplify right side
   1,427.88x = 1,651,685.72
5. Step 5: Solve for x
   x = 1,651,685.72/1,427.88
6. Step 6: Final answer
   x = 1,156.74