Finding the Fourth Proportional to 1,319.15, 1,978.71 and 538.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,319.15 : 1,978.71 = 538.99 : x
2. Step 2: Convert to fraction form
   1,319.15/1,978.71 = 538.99/x
3. Step 3: Cross multiply
   1,319.15x = 1,978.71 × 538.99
4. Step 4: Simplify right side
   1,319.15x = 1,066,499.96
5. Step 5: Solve for x
   x = 1,066,499.96/1,319.15
6. Step 6: Final answer
   x = 808.47