Finding the Fourth Proportional to 1,538.95, 2,123.78 and 840.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.95 : 2,123.78 = 840.32 : x
2. Step 2: Convert to fraction form
   1,538.95/2,123.78 = 840.32/x
3. Step 3: Cross multiply
   1,538.95x = 2,123.78 × 840.32
4. Step 4: Simplify right side
   1,538.95x = 1,784,654.81
5. Step 5: Solve for x
   x = 1,784,654.81/1,538.95
6. Step 6: Final answer
   x = 1,159.66