Need help with the following question:

The samples come from a normal distribution with unknown standard

deviations. Some critical T percentiles. t_{0.95,5}=2.015,

t_{0.975,5}=2.571, t_{0.95,6}= 1.943, t_{0.975,6}=2.447,

t_{0.95,7}=1.895, t_{0.975,7}= 2.365

(a) Compute a 95% confidence interval for population mean u

given the sample mean is 2.7, sample standard deviation is 1.2, and

sample size n is 6.

(b) Compute a 90% confidence interval for population mean u

given the sample mean is 3.5, sample standard deviation is 0.9, and

sample size n is 7.

(c) Compute a 95% lower confidence bound for population mean u

given the sample mean is 4.8, sample standard deviation is 2.1, and

sample size n is 6.