(c) Assuming that any concerns about data collection can be resolved, evaluate the evidence that hepatitis C status and tattoo status are related in the relevant population. If you conclude that there is a relationship, describe it. Use a 1% significance level

(THIS IS WORTH 11 MARKS)

[15 marks] Hepatitis C is a blood-borne infection with potentially serious consequences. Identication of social and environmental risk factors is important because Hepatitis C can go undetected for years after infection. A study conducted in Texas in 1991-2 examined whether the incidence of hepatitis C was related to whether people had tattoos and where they obtained their tattoos. Data were obtained from existing medical records of patients who were being treated for conditions that were not blood-related disorders. The patients were classied according to hepatitis C status (whether they had it or not) and tattoo status (tattoo from tattoo parlour, tattoo obtained elsewhere, or no tattoo). The data are summarised in the following table. Tattoo? l Has Hep C No Hep C Tattoo (parlour) 17 43 Tattoo (elsewhere) 8 54 No tattoo 22 461