Finding the Fourth Proportional to 947.86, 1,308.88 and 916.88

Step by Step Solution

1. Step 1: Write the proportion equation
   947.86 : 1,308.88 = 916.88 : x
2. Step 2: Convert to fraction form
   947.86/1,308.88 = 916.88/x
3. Step 3: Cross multiply
   947.86x = 1,308.88 × 916.88
4. Step 4: Simplify right side
   947.86x = 1,200,085.89
5. Step 5: Solve for x
   x = 1,200,085.89/947.86
6. Step 6: Final answer
   x = 1,266.10