Statistics question with word doc attached

1. A sample survey to estimate the fast-food market in a large city was kept small enough to allow repeated follow-up. The high response rate meant that the sample was essentially random. The survey recorded the number of fast-food meals eaten by each person in the previous 7 days, and the average is 0.82 with standard deviation of 0.48. Sample size of 180.Calculate a 95% confidence interval for the mean of the whole population of this city. You may assume a two-tailed test.

2.From a large class, a sample of 4 grades were drawn: 64, 66, 78, and 87. From a second large class, an independent sample of 3 grades were drawn: 59, 78, and 93. Test if the two class have equivalent performance, assume 5% level of significance. You may make necessary assumptions.

3. Now repeat Q.2 but test if the first class performs better than the second.

4.In a large American university in 1969, the male and female professors were sampled independently, yielding the following annual salaries (in thousands of dollars):

Test if there was a wage discriminationagainst women. Assume 1% level of significance.