can you please help me answer these questions

Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value to /2. (b) find the critical value z,/2, or (c) state that neither the normal distribution nor the t distribution applies. Here are summary statistics for randomly selected weights of newborn girls: n = 153, x= 33.4 hg, s=6.9 hg. The confidence level is 95%. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. ta/2= (Round to two decimal places as needed.) O B. Za/2 = (Round to two decimal places as needed.) O C. Neither the normal distribution nor the t distribution applies.Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value to /2. (b) find the critical value Za/2, or (c) state that neither 40- the normal distribution nor the t distribution applies. 30- The confidence level is 99%, 6 = 3949 thousand dollars, and the histogram of 60 player salaries (in thousands of dollars) of football players on a team is as shown. Frequency 20- 10- 0- 0 4000 8000 12000 16000 20000 Salary (thousands of dollars) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. ta/2= (Round to two decimal places as needed.) O B. Za/2= (Round to two decimal places as needed.) O C. Neither the normal distribution nor the t distribution applies.You are the operations manager for an airline and you are considering a higher fare level for passengers in aisle seats. How many randomly selected air passengers must you survey? Assume that you want to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage. Complete parts (a) and (b) below. a. Assume that nothing is known about the percentage of passengers who prefer aisle seats. n= (Round up to the nearest integer.) b. Assume that a prior survey suggests that about 38% of air passengers prefer an aisle seat. (Round up to the nearest integer.)In a study of government financial aid for college students, it becomes necessary to estimate the percentage of full-time college students who earn a bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.01 margin of error and use a confidence level of 90%. Complete parts (a) through (c) below. a. Assume that nothing is known about the percentage to be estimated. n = (Round up to the nearest integer.) b. Assume prior studies have shown that about 55% of full-time students earn bachelor's degrees in four years or less. n= (Round up to the nearest integer.) c. Does the added knowledge in part (b) have much of an effect on the sample size? O A. Yes, using the additional survey information from part (b) only slightly increases the sample size. O B. No, using the additional survey information from part (b) only slightly reduces the sample size. O C. No, using the additional survey information from part (b) does not change the sample size. O D. Yes, using the additional survey information from part (b) dramatically reduces the sample size