1. The problem statement, all variables and given/known data A random sample of 30 rats has 18 females and 12 males. If last year's proportion of females treated was 0.65, do the above data confirm that this year the proportion of females is different than last year? 2. Relevant equations p = treated / total If using standard normal: z = (value - mean) / (standard deviation / squareroot(sample size) ) 3. The attempt at a solution I *think* the null hypothesis is p = 0.65 and the alternative hypothesis is p ≠ 0.65 What I'm stuck on now is I don't know what test statistic to use to find the p value to decide if I should reject the null hypothesis. Not sure if normal or binomial is supposed to be used and how to do the calculations for this.