determine the sampling error if the graded point averages for 10 randomly selected students from a class of 125 students has a mean of x=1.8 . Assume the grade point average of the 125 students has a mean of u=2.2

a random sample of 150 students has a grade point average of 2.86 and with a standard deviation of 0.78. Construct the confidence interval for the population mean,u,if c=0.98

a random sample of 150 students has a grade point average of 2.86 and with a standard deviation of 0.78. construct the confidence interval for the population mean,u,if c=0.98
Please help