Finding the Fourth Proportional to 1,428.69, 1,973.59 and 1,353.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.69 : 1,973.59 = 1,353.88 : x
2. Step 2: Convert to fraction form
   1,428.69/1,973.59 = 1,353.88/x
3. Step 3: Cross multiply
   1,428.69x = 1,973.59 × 1,353.88
4. Step 4: Simplify right side
   1,428.69x = 2,671,995.71
5. Step 5: Solve for x
   x = 2,671,995.71/1,428.69
6. Step 6: Final answer
   x = 1,870.24