Minodixil was investigated ina large ,27-centre study where patients were randomly assigned to receive topical minodixil or an identical appearing placebo.ignoring the centre tocentre variation,suppose the prelliminary results were as follows group 1 n=310,p=32 and group 2 n=309,p=20 construct a 95% confidence interval for the difference in proportions of patients with new hair growth for the two groups using the given data.