Finding the Fourth Proportional to 1,190.40, 1,642.83 and 666.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,190.40 : 1,642.83 = 666.42 : x
2. Step 2: Convert to fraction form
   1,190.40/1,642.83 = 666.42/x
3. Step 3: Cross multiply
   1,190.40x = 1,642.83 × 666.42
4. Step 4: Simplify right side
   1,190.40x = 1,094,814.77
5. Step 5: Solve for x
   x = 1,094,814.77/1,190.40
6. Step 6: Final answer
   x = 919.70