Statins are widely prescribed to treat high cholesterol. However, they are known to have some unfortunate side-effects. One study advertised for volunteers aged 30 - 50 years who were either currently taking statins under medical supervision, or not taking statins at all. A small fee was offered to accepted participants, and evidence of identity was required (e.g., driver's licence). Volunteers were screened to ensure that none had the same address, or belonged to the same family, and no more than 5 shared the same postcode. No applications were accepted from addresses that lay outside Australia or appeared to be aliases. After screening, accepted participants were asked to maintain a daily diary for a week via an online form that asked about a range of possible side-effects. Confirmation of statin dosage (if any) was obtained from their doctor. The table below summarises participants' journal entries regarding back pain, classified by statin dose.

	0mg	10mg	20mg	40mg	80mg
Back Pain	15	55	9	11	15
No Back Pain	251	816	66	72	88

Test the hypothesis that, among Australians aged 30 - 50 years, occurrence of back pain is unrelated to statin dose. Include discussion of assumptions and take appropriate action regarding any problems. If you conclude that there is a relationship, describe it. Use a 5% significance level. You may assume that the checks on identity and location are adequate.