Finding the Fourth Proportional to 1,428.04, 1,970.62 and 807

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.04 : 1,970.62 = 807 : x
2. Step 2: Convert to fraction form
   1,428.04/1,970.62 = 807/x
3. Step 3: Cross multiply
   1,428.04x = 1,970.62 × 807
4. Step 4: Simplify right side
   1,428.04x = 1,590,290.34
5. Step 5: Solve for x
   x = 1,590,290.34/1,428.04
6. Step 6: Final answer
   x = 1,113.62