Finding the Fourth Proportional to 1,356.48, 1,870.56 and 890.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.48 : 1,870.56 = 890.88 : x
2. Step 2: Convert to fraction form
   1,356.48/1,870.56 = 890.88/x
3. Step 3: Cross multiply
   1,356.48x = 1,870.56 × 890.88
4. Step 4: Simplify right side
   1,356.48x = 1,666,444.49
5. Step 5: Solve for x
   x = 1,666,444.49/1,356.48
6. Step 6: Final answer
   x = 1,228.51