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.