Finding the Fourth Proportional to 1,561.34, 2,153.40 and 970.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.34 : 2,153.40 = 970.76 : x
2. Step 2: Convert to fraction form
   1,561.34/2,153.40 = 970.76/x
3. Step 3: Cross multiply
   1,561.34x = 2,153.40 × 970.76
4. Step 4: Simplify right side
   1,561.34x = 2,090,434.58
5. Step 5: Solve for x
   x = 2,090,434.58/1,561.34
6. Step 6: Final answer
   x = 1,338.87