Why students lose marks in statistics, and how not to

Statistics is the unit students in this college most often decide they cannot do. It is also the unit where the marks are most reliable, because the answer is either right or it is not, and there is no examiner's opinion in it.

The four things that cost marks

1. Not writing the formula. The formula carries a mark of its own. Write it before you substitute, every time, even when you can do the sum in your head.
2. Not showing the table. For grouped data, the working table — class, frequency, midpoint, fx — carries marks whether or not the final answer is right.
3. Arithmetic in a hurry. Check the total of the frequency column against N before going on. Thirty seconds there saves the whole question.
4. No unit in the answer. "Mean = 42" is not the answer. "Mean = ₹42 per household" is.

What you need

A calculator is permitted. Bring one you have used before — the examination hall is not the place to learn where the memory button is.