Finding the Fourth Proportional to 2,133.81, 3,199.91 and 978.75

Step by Step Solution

1. Step 1: Write the proportion equation
   2,133.81 : 3,199.91 = 978.75 : x
2. Step 2: Convert to fraction form
   2,133.81/3,199.91 = 978.75/x
3. Step 3: Cross multiply
   2,133.81x = 3,199.91 × 978.75
4. Step 4: Simplify right side
   2,133.81x = 3,131,907.02
5. Step 5: Solve for x
   x = 3,131,907.02/2,133.81
6. Step 6: Final answer
   x = 1,467.75