Finding the Fourth Proportional to 1,788.47, 2,467.98 and 991.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,788.47 : 2,467.98 = 991.77 : x
2. Step 2: Convert to fraction form
   1,788.47/2,467.98 = 991.77/x
3. Step 3: Cross multiply
   1,788.47x = 2,467.98 × 991.77
4. Step 4: Simplify right side
   1,788.47x = 2,447,668.52
5. Step 5: Solve for x
   x = 2,447,668.52/1,788.47
6. Step 6: Final answer
   x = 1,368.59