What is the smallest sample size required to provide a 95% confidence interval for a mean, if it important that the interval be no longer than 1cm? you may assume that the population is normal with variance 9cm2. 3p 6. it is known that the standard deviation of the scores in a math exam was 2.4, σ-2.4, and a sample of 36 students scored an average of 5.5. with this data, can the hypothesis be confirmed that the average test score was 8p 5.8 with a significance level of 5%?