Finding the Fourth Proportional to 1,570.78, 2,167.51 and 981.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.78 : 2,167.51 = 981.10 : x
2. Step 2: Convert to fraction form
   1,570.78/2,167.51 = 981.10/x
3. Step 3: Cross multiply
   1,570.78x = 2,167.51 × 981.10
4. Step 4: Simplify right side
   1,570.78x = 2,126,544.06
5. Step 5: Solve for x
   x = 2,126,544.06/1,570.78
6. Step 6: Final answer
   x = 1,353.81