Finding the Fourth Proportional to 716,786.35, 989,146.42 and 390,105.89

Step by Step Solution

1. Step 1: Write the proportion equation
   716,786.35 : 989,146.42 = 390,105.89 : x
2. Step 2: Convert to fraction form
   716,786.35/989,146.42 = 390,105.89/x
3. Step 3: Cross multiply
   716,786.35x = 989,146.42 × 390,105.89
4. Step 4: Simplify right side
   716,786.35x = 385,871,842,302.72
5. Step 5: Solve for x
   x = 385,871,842,302.72/716,786.35
6. Step 6: Final answer
   x = 538,335.93