An article in journal of the american statistical association (1990, vol. 85, pp. 972–985) measured weight of 30 rats under experiment controls. suppose that there are 12 underweight rats. (a) calculate a 99% two-sided confidence interval on the true proportion of rats that would show underweight from the experiment. round your answers to 3 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) using the point estimate of p obtained from the preliminary sample, what sample size is needed to be 99% confident that the error in estimating the true value of p is no more than 0.02? n equals (c) how large must the sample be if we wish to be at least 99% confident that the error in estimating p is less than 0.02, regardless of the true value of p?