Can you please explain the 3 question of the practice exam.
Application of functions is easy but do I have to subtract the mean from all the datapoints first and then divide it by std deviation. It will really be helpful if there were some notes or pdfs we could refer to for better understanding.
When standardizing you can either:
- subtract the mean and divide by the stddev.S in one formula (i.e (B3(for example) - AVERAGE(B3:B81))/STDDEV.S(B3:B81)).
- Divide the standardization process into two steps: First create a new dataset which is the result of subtracting the mean, then take each value in that dataset and divide by the stddev.
Regardless of the approach, both solutions will provide the same results.