Examination question.to illustrate the use of the correction for continuity, we shall again consider Example 5.7.6. In that example an examination contains 99 questions of varying difficulty and it is desired to determine , where X denotes the total number of questions that a particular student answers correctly. Then, under the conditions of the example, it is found from the central limit theorem that the discrete distribution of X could be approximated by a normal distribution with mean 49.5 and standard deviation 4.08.