Population Standard Deviation

1. In the following situations, indicate whether you’d use the normal distribution, the t distribution, or neither.a. The population is normally distributed, and you know the population standard deviation.b. You don’t know the population standard deviation, and the sample size is 35.c. The sample size is 22, and the population is normally distributed.d. The sample size is 12, and the population is not normally distributed.e. The sample size is 45, and you know the population standard deviation.2. The prices of used books at a large college bookstore are normally distributed. If a sample of 23 used books from this store has a mean price of $27.50 with a standard deviation of $6.75, use Table 10.1 in your textbook to calculate the following for a 95% confidence level about the population mean. Be sure to show your work.a. Degrees of freedomb. The critical value of tc. The margin of errord. The confidence interval for a 95% confidence level3. Statistics students at a state college compiled the following two-way table from a sample of randomly selected students at their college:For more information on Population Standard Deviation check on:https://en.wikipedia.org/wiki/Standard_deviation