Question 28 Students had a mean grade of 75% in the past. After applying a new teaching method, the following scores were recorded for a sample of 13 random students: Scores 83 82 74 85 76 73 85 66 66 82 80 84 72 In order to construct a 95% confidence interval for the new mean grade, we should use: O 1-PropZInt 2-SampTint 2-PropZInt O ZInterval 2-SampZInt O TInterval