6. The following are randomly selected scores in Math 11 of 12 students. \( 75,65,76,80,85,77,81,83,80,70,71 \), and 69 .
A. Find a \( 99 \% \) confidence interval for the mean score of all the students, assuming that the students' score is approximately normally distributed. B. Solve for the upper and the lower confidence limits.