Finding the Fourth Proportional to 1,538.91, 2,123.69 and 840.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.91 : 2,123.69 = 840.30 : x
2. Step 2: Convert to fraction form
   1,538.91/2,123.69 = 840.30/x
3. Step 3: Cross multiply
   1,538.91x = 2,123.69 × 840.30
4. Step 4: Simplify right side
   1,538.91x = 1,784,532.51
5. Step 5: Solve for x
   x = 1,784,532.51/1,538.91
6. Step 6: Final answer
   x = 1,159.61