Finding the Fourth Proportional to 1,074.21, 1,609.20 and 707.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,074.21 : 1,609.20 = 707.89 : x
2. Step 2: Convert to fraction form
   1,074.21/1,609.20 = 707.89/x
3. Step 3: Cross multiply
   1,074.21x = 1,609.20 × 707.89
4. Step 4: Simplify right side
   1,074.21x = 1,139,136.59
5. Step 5: Solve for x
   x = 1,139,136.59/1,074.21
6. Step 6: Final answer
   x = 1,060.44