Finding the Fourth Proportional to 1,570.01, 2,166.64 and 861.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.01 : 2,166.64 = 861.89 : x
2. Step 2: Convert to fraction form
   1,570.01/2,166.64 = 861.89/x
3. Step 3: Cross multiply
   1,570.01x = 2,166.64 × 861.89
4. Step 4: Simplify right side
   1,570.01x = 1,867,408.61
5. Step 5: Solve for x
   x = 1,867,408.61/1,570.01
6. Step 6: Final answer
   x = 1,189.42