Finding the Fourth Proportional to 1,345.26, 1,855.80 and 820.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.26 : 1,855.80 = 820.38 : x
2. Step 2: Convert to fraction form
   1,345.26/1,855.80 = 820.38/x
3. Step 3: Cross multiply
   1,345.26x = 1,855.80 × 820.38
4. Step 4: Simplify right side
   1,345.26x = 1,522,461.20
5. Step 5: Solve for x
   x = 1,522,461.20/1,345.26
6. Step 6: Final answer
   x = 1,131.72