Hello, I was just wondering if someone could help explain how to solve the problems? I know the answers, but am not sure how to go about solving the problems.

4. A random sample of 45 perch from Lake Erie had a sample mean weight of 5.91 pounds and sample standard deviation of 0.85 pounds. Use a significance level of a = 0.05. Create the appropriate confidence interval and perform hypotheses testing with the null hypothesis that the mean weight of perch in Lake Erie is 6.3 pounds and alternative hypothesis that the mean weight is not 6.3 pounds. Justify the assumptions needed.5. A large shipping company in Ohio claims that 90% of its customers are very satisfied with the service they receive. In an effort to show that this proportion is too high, we randomly survey 200 customers. Among the sampled customers, 88% say they are very satisfied. Based on these findings, can we reject the claim that 90% of the customers are very satisfied and accept our hypothesis? Use a 0.05 level of significance. State the hypotheses and interpret your results. Also, justify the assumptions needed