please help with this question on medical statistics

Question 4 [10 marks] Researchers wanted to study the association between CD4 count and initial response to anti-retroviral therapy among HIV positive patients. A random sample of 1000 HIV positive patients were enrolled into the study. The baseline CD4 count was determined at the start of therapy. Participants were split into two groups; those with a CD4 count less than 350 and those with a CD4 count of 350 or greater. The results are summarized in the table below. Use this information to answer questions. (All final answers should be expressed to 2 decimal places); CD4 350 Total Response 206 No response 376 418 794 Total 503 497 1000 a) Make hypotheses of association between CD4 count and response to therapy (Null and Alternative hypotheses). [2 marks] b) Calculate the Pearson Chi Square test (X) [5 marks]