Finding the Fourth Proportional to 1,421.51, 1,961.69 and 824.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.51 : 1,961.69 = 824.12 : x
2. Step 2: Convert to fraction form
   1,421.51/1,961.69 = 824.12/x
3. Step 3: Cross multiply
   1,421.51x = 1,961.69 × 824.12
4. Step 4: Simplify right side
   1,421.51x = 1,616,663.84
5. Step 5: Solve for x
   x = 1,616,663.84/1,421.51
6. Step 6: Final answer
   x = 1,137.29