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Students always wonder why do we reject the null hypothesis when the p-value is less than the level of significance. To understand how hypothesis testing works, students can read more here. So [...]

All A-level students should know that when you have a non-normal distribution and a sufficiently large sample size n, we can approximate it to a normal distribution. So what happens here? Why is [...]

This is question in relation to the birthday paradox we discussed earlier. A room contains randomly chosen people. Assume that a randomly chosen people is equally likely to have been born on any [...]

This is a question taken from the 2008 H1 paper. I think it is a simple question that test students on their understanding of what standard deviation mean. An examination is marked out of 100. It [...]

A man looks at his watch at a random time between mid-day and 1300H. What is the probability that the angle between the hands of the watch is less than ? Ans:

Some of your school notes will mention and explain the definition of unbiased and consistency. But let us just discuss what unbiased means as we do see it quite often in A-level. What does its [...]

This is an interesting question from ACJC’2014 Prelim Exam. I feel that it test a lot on students’ understanding of the normal distribution curve. The height , in centimetres, of a [...]

One of the confusing thing that many JC2s stumble upon is that variances in A-levels. This is partly attributed to the lack of understanding and introduction of the concept. By hypothesis [...]