Finding the Fourth Proportional to 1,002.21, 1,510.80 and 935.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.21 : 1,510.80 = 935.31 : x
2. Step 2: Convert to fraction form
   1,002.21/1,510.80 = 935.31/x
3. Step 3: Cross multiply
   1,002.21x = 1,510.80 × 935.31
4. Step 4: Simplify right side
   1,002.21x = 1,413,066.35
5. Step 5: Solve for x
   x = 1,413,066.35/1,002.21
6. Step 6: Final answer
   x = 1,409.95