Finding the Fourth Proportional to 938.72, 1,407.31 and 707.15

Step by Step Solution

1. Step 1: Write the proportion equation
   938.72 : 1,407.31 = 707.15 : x
2. Step 2: Convert to fraction form
   938.72/1,407.31 = 707.15/x
3. Step 3: Cross multiply
   938.72x = 1,407.31 × 707.15
4. Step 4: Simplify right side
   938.72x = 995,181.02
5. Step 5: Solve for x
   x = 995,181.02/938.72
6. Step 6: Final answer
   x = 1,060.14