Finding the Fourth Proportional to 1,418.72, 2,128.01 and 870.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,418.72 : 2,128.01 = 870.08 : x
2. Step 2: Convert to fraction form
   1,418.72/2,128.01 = 870.08/x
3. Step 3: Cross multiply
   1,418.72x = 2,128.01 × 870.08
4. Step 4: Simplify right side
   1,418.72x = 1,851,523.95
5. Step 5: Solve for x
   x = 1,851,523.95/1,418.72
6. Step 6: Final answer
   x = 1,305.07