Finding the Fourth Proportional to 1,189.80, 1,641.42 and 692.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.80 : 1,641.42 = 692.10 : x
2. Step 2: Convert to fraction form
   1,189.80/1,641.42 = 692.10/x
3. Step 3: Cross multiply
   1,189.80x = 1,641.42 × 692.10
4. Step 4: Simplify right side
   1,189.80x = 1,136,026.78
5. Step 5: Solve for x
   x = 1,136,026.78/1,189.80
6. Step 6: Final answer
   x = 954.80