Just gave a quiz, and among others, the following problem
3) A set of 11 data values has a mean of 8 and a std dev of 2. At least one of the data items is the value 8. If this value is removed, without replacement from the data set, what will be the std dev of the remaining data? Show all work or calculator entry and results.
I had assumed they would find this very tough, but was pleased with the results.