Finding the Fourth Proportional to 1,570.09, 2,166.48 and 897.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.09 : 2,166.48 = 897.78 : x
2. Step 2: Convert to fraction form
   1,570.09/2,166.48 = 897.78/x
3. Step 3: Cross multiply
   1,570.09x = 2,166.48 × 897.78
4. Step 4: Simplify right side
   1,570.09x = 1,945,022.41
5. Step 5: Solve for x
   x = 1,945,022.41/1,570.09
6. Step 6: Final answer
   x = 1,238.80