Are these correct?

QUESTION 1 1. C8 Q1 V2: A random sample of 100 students is taken from a larger population of students in a multi- lecture course and the sample mean (average) of their final grades is found to be 62.25. Suppose it is known that the population standard deviation is 3.2. You wish to create a 94% confidence interval. Which of the following statements is most correct? The za/2 (found from R) used to calculate the 94% confidence interval is 1.880794. The Za/2 (found from R) used to calculate the 94% confidence interval is 0.03. O The Za/2 (found from R) used to calculate the 94% confidence interval is 1.554774. The Za/2 (found from R) used to calculate the 94% confidence interval is 2.17009. 1 points QUESTION 2 1. C8 Q2 V3: A random sample of 16 students is taken from a larger normal population of students in a multi-lecture course and the sample mean (average) of their final grades is found to be 62.25. Suppose it is known that the sample standard deviation is 3.2. You wish to create a 96% confidence interval for the true population mean. Which of the following statements is most correct? The ta/2,n-1 (found from R) that is needed to calculate the 96% confidence interval is 2.24854. The ta/2,n-1 (found from R) used to calculate the 96% confidence interval is 0.02. O The ta/2,n-1 (found from R) used to calculate the 96% confidence interval is 1.877739. The ta/2,n-1 (found from R) used to calculate the 96% confidence interval is 2.60248. 1 points QUESTION 3 1. C8 Q8 V2: A random sample of 100 students is taken from a larger population of students in a multi- lecture course and the sample mean (average) of their final grades is found to be 63.25. Suppose that the population standard deviation is known to be 4. Which of the following is correct? (Note that you can answer these questions from understanding gleaned in lecture and lab, but may find R helpful.) A 99% Z confidence interval for the true population mean that is calculated from this sample O data of 100 students will be narrower than a 90% Z confidence interval for the true population mean that is calculated from this sample data of 100 students. A 99% Z confidence interval for the true population mean that is calculated from this sample data of 100 students will be wider than a 95% Z confidence interval for the true population mean that is calculated from this sample data of 100 students. The true population mean grade is 63.25. A 95% Z confidence interval for the true population mean that is calculated from this sample O data of 100 students would be narrower than a 95% Z confidence interval for the true population mean that is calculated from a sample of 144 students from the same population. 1 points