A student calculated the mean of 5 numbers as 45.3. While rechecking his working, he discovered that his total was short by 20.5. What is the correct mean of the 5 numbers?
Worked solution (try it first)
His wrong total was 5×45.3=226.5.
It was short by 20.5, so the right total is 226.5+20.5=247.