Finding the Fourth Proportional to 1,388.04, 1,914.95 and 890.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.04 : 1,914.95 = 890.60 : x
2. Step 2: Convert to fraction form
   1,388.04/1,914.95 = 890.60/x
3. Step 3: Cross multiply
   1,388.04x = 1,914.95 × 890.60
4. Step 4: Simplify right side
   1,388.04x = 1,705,450.02
5. Step 5: Solve for x
   x = 1,705,450.02/1,388.04
6. Step 6: Final answer
   x = 1,228.67