Finding the Fourth Proportional to 1,415.99, 1,954.30 and 786.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.99 : 1,954.30 = 786.72 : x
2. Step 2: Convert to fraction form
   1,415.99/1,954.30 = 786.72/x
3. Step 3: Cross multiply
   1,415.99x = 1,954.30 × 786.72
4. Step 4: Simplify right side
   1,415.99x = 1,537,484.93
5. Step 5: Solve for x
   x = 1,537,484.93/1,415.99
6. Step 6: Final answer
   x = 1,085.80