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 90% two-sided confidence interval on the true proportion of rats that would show underweight from the experiment. Round your answers to 3 decimal places. b. Using the point estimate of p obtained from the preliminary sample, what sample size is needed to be 90% confident that the error in estimating the true value of p is no more than 0.02? c. How large must the sample be if we wish to be at least 90% confident that the error in estimating p is less than 0.02, regardless of the true value of p?
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 90% two-sided confidence interval on the true proportion of rats that would
show underweight from the experiment. Round your answers to 3 decimal places.
b. Using the point estimate of p obtained from the preliminary sample, what
needed to be 90% confident that the error in estimating the true value of p is no more
than 0.02?
c. How large must the sample be if we wish to be at least 90% confident that the error in
estimating p is less than 0.02, regardless of the true value of p?
Trending now
This is a popular solution!
Step by step
Solved in 4 steps