please solve them correctly

Items in this section (#29 through #32) refer to the following scenario. A school district researcher randomly selected 40 sixth-grade students in the district to pilot a new mathematics test. The mean score for these students was 78 (out of 100 possible) and the standard deviation was 12. ## ## 29. *What is the standard error of the mean for this test?* ** * #### 30. *What critical value should you use if you want to construct a 95% confidence* *interval for the population mean? (Give your answer to two decimal places.)* #### 31. *What is the margin of error for the mean of this test?* ## ## 32. *What is the 95% confidence interval for the population mean?*