You want to test whether or not the following sample of 30 observations follows a normal distribution. the mean of the sample equals 11.83 and the standard deviation equals 4.53. 2 3 5 5 7 8 8 9 9 10 11 11 12 12 12 12 13 13 13 14 15 15 15 16 16 17 17 18 18 19 the hypothesis is to be tested at the 5% level of significance. if the expected frequencies for the classes are equal to 5, what is the critical value of the test statistic? select one: a. 1.645 b. 1.96 c. 7.815 d. 12.592