Finding the Fourth Proportional to 1,368.48, 1,887.72 and 870.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,368.48 : 1,887.72 = 870.12 : x
2. Step 2: Convert to fraction form
   1,368.48/1,887.72 = 870.12/x
3. Step 3: Cross multiply
   1,368.48x = 1,887.72 × 870.12
4. Step 4: Simplify right side
   1,368.48x = 1,642,542.93
5. Step 5: Solve for x
   x = 1,642,542.93/1,368.48
6. Step 6: Final answer
   x = 1,200.27