Finding the Fourth Proportional to 1,401.67, 1,934.22 and 780.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.67 : 1,934.22 = 780.67 : x
2. Step 2: Convert to fraction form
   1,401.67/1,934.22 = 780.67/x
3. Step 3: Cross multiply
   1,401.67x = 1,934.22 × 780.67
4. Step 4: Simplify right side
   1,401.67x = 1,509,987.53
5. Step 5: Solve for x
   x = 1,509,987.53/1,401.67
6. Step 6: Final answer
   x = 1,077.28