Finding the Fourth Proportional to 1,061.78, 1,593.12 and 978

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.78 : 1,593.12 = 978 : x
2. Step 2: Convert to fraction form
   1,061.78/1,593.12 = 978/x
3. Step 3: Cross multiply
   1,061.78x = 1,593.12 × 978
4. Step 4: Simplify right side
   1,061.78x = 1,558,071.36
5. Step 5: Solve for x
   x = 1,558,071.36/1,061.78
6. Step 6: Final answer
   x = 1,467.41