Need to do a chi squared test on the following data. Fifty patients

Need to do a chi squared test on the following data. Fifty patients wounds were treated with two different bandage types: A and B. 23 were given type A and 27 were given type B. Dichotomous data was collected over a 2 quarter time frame (6 months). The results were:  Type A: 19 improved and 4 did not  Type B: 14 improved and 13 did not  Questions:  What are the variables?  What is the hypothesis?  What are expected frequencies?  Are 2 variables independent?  Calculate CI's of difference of improved.