Finding the Fourth Proportional to 1,189.98, 1,638.78 and 1,164.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.98 : 1,638.78 = 1,164.54 : x
2. Step 2: Convert to fraction form
   1,189.98/1,638.78 = 1,164.54/x
3. Step 3: Cross multiply
   1,189.98x = 1,638.78 × 1,164.54
4. Step 4: Simplify right side
   1,189.98x = 1,908,424.86
5. Step 5: Solve for x
   x = 1,908,424.86/1,189.98
6. Step 6: Final answer
   x = 1,603.75